79529981 has 2 divisors, whose sum is σ = 79529982. Its totient is φ = 79529980.

The previous prime is 79529939. The next prime is 79529993. The reversal of 79529981 is 18992597.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78943225 + 586756 = 8885^2 + 766^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79529981 is a prime.

It is a super-2 number, since 2×79529981² = 12650035755720722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79520981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39764990 + 39764991.

It is an arithmetic number, because the mean of its divisors is an integer number (39764991).

Almost surely, 2^79529981 is an apocalyptic number.

It is an amenable number.

79529981 is a deficient number, since it is larger than the sum of its proper divisors (1).

79529981 is an equidigital number, since it uses as much as digits as its factorization.

79529981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 408240, while the sum is 50.

The square root of 79529981 is about 8917.9583425804. The cubic root of 79529981 is about 430.0414256106.

The spelling of 79529981 in words is "seventy-nine million, five hundred twenty-nine thousand, nine hundred eighty-one".