79289981 has 4 divisors (see below), whose sum is σ = 79367772. Its totient is φ = 79212192.

The previous prime is 79289963. The next prime is 79290007. The reversal of 79289981 is 18998297.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18998297 = 541 ⋅35117.

It can be written as a sum of positive squares in 2 ways, for example, as 74736025 + 4553956 = 8645^2 + 2134^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79289981 is a prime.

It is a super-2 number, since 2×79289981² = 12573802173960722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79289381) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37346 + ... + 39411.

It is an arithmetic number, because the mean of its divisors is an integer number (19841943).

Almost surely, 2^79289981 is an apocalyptic number.

It is an amenable number.

79289981 is a deficient number, since it is larger than the sum of its proper divisors (77791).

79289981 is a wasteful number, since it uses less digits than its factorization.

79289981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77790.

The product of its digits is 653184, while the sum is 53.

The square root of 79289981 is about 8904.4921809163. The cubic root of 79289981 is about 429.6084067869.

The spelling of 79289981 in words is "seventy-nine million, two hundred eighty-nine thousand, nine hundred eighty-one".