83709981 has 12 divisors (see below), whose sum is σ = 121072380. Its totient is φ = 55733760.

The previous prime is 83709973. The next prime is 83710009. The reversal of 83709981 is 18990738.

It can be written as a sum of positive squares in 2 ways, for example, as 26101881 + 57608100 = 5109^2 + 7590^2 .

It is not a de Polignac number, because 83709981 - 2³ = 83709973 is a prime.

It is a super-2 number, since 2×83709981² = 14014721838040722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83709931) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1725 + ... + 13053.

It is an arithmetic number, because the mean of its divisors is an integer number (10089365).

Almost surely, 2^83709981 is an apocalyptic number.

It is an amenable number.

83709981 is a deficient number, since it is larger than the sum of its proper divisors (37362399).

83709981 is a wasteful number, since it uses less digits than its factorization.

83709981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12156 (or 12153 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The square root of 83709981 is about 9149.3158760642. The cubic root of 83709981 is about 437.4473075043.

The spelling of 83709981 in words is "eighty-three million, seven hundred nine thousand, nine hundred eighty-one".