1 million digits of PI 1 billion digits of PI Mandelbrot set Explorer

Number 1981

Properties of the number 1981

Prime Factorization 7 x 283
Divisors 1, 7, 283, 1981
Count of divisors 4
Sum of divisors 2272
Previous integer 1980
Next integer 1982
Is prime? NO
Previous prime 1979
Next prime 1987
1981st prime number
calculating, please wait
Is a Fibonacci number? NO
Zeckendorf representation 1597 + 377 + 5 + 2
Is a Pell number? NO
Is a regular number? NO
Is a perfect number? NO
Is a perfect square number? NO
Is a perfect cube number? NO
Is power of 2? NO
Is power of 3? NO
Square 19812 3924361
Square root √1981 44.508426168536
Cube 19813 7774159141
Cubic root ∛1981 12.559185985894
Natural logarithm 7.5913570466986
Decimal logarithm 3.2968844755385

Trigonometry of the number 1981

1981 modulo 360° 181°
Sine of 1981 radians 0.97460816499552
Cosine of 1981 radians -0.22391722739458
Tangent of 1981 radians -4.352537660169
Sine of 1981 degrees -0.017452406437288
Cosine of 1981 degrees -0.99984769515639
Tangent of 1981 degrees 0.017455064928222
1981 degrees in radiants 34.574972482008
1981 radiants in degrees 113502.93921542

Base conversion of the number 1981

Binary 11110111101
Octal 3675
Duodecimal 1191
Hexadecimal 7bd
« Previous Next »

Recommended Books

Looking for good books to read? Take a look at these books if you want to know more about the theory of numbers
To guide today's students through the key milestones and developments in number theory
Read it »
A comprehensive introduction to number theory, with complete proofs, worked examples, and exercises.
Read it »
Several of its challenges are so easy to state that everyone can understand them, and yet no-one has ever been able to resolve them.
Read it »
In addition to covering the basics, it offers an outstanding introduction to partitions, multiplicativity-divisibility, and more.
Read it »