79555621 has 4 divisors (see below), whose sum is σ = 81496044. Its totient is φ = 77615200.

The previous prime is 79555591. The next prime is 79555657. The reversal of 79555621 is 12655597.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12655597 = 557 ⋅22721.

It can be written as a sum of positive squares in 2 ways, for example, as 43375396 + 36180225 = 6586^2 + 6015^2 .

It is a cyclic number.

It is not a de Polignac number, because 79555621 - 2⁵ = 79555589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79555681) 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, 970150 + ... + 970231.

It is an arithmetic number, because the mean of its divisors is an integer number (20374011).

Almost surely, 2^79555621 is an apocalyptic number.

It is an amenable number.

79555621 is a deficient number, since it is larger than the sum of its proper divisors (1940423).

79555621 is a wasteful number, since it uses less digits than its factorization.

79555621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1940422.

The product of its digits is 94500, while the sum is 40.

The square root of 79555621 is about 8919.3957754996. The cubic root of 79555621 is about 430.0876349239.

The spelling of 79555621 in words is "seventy-nine million, five hundred fifty-five thousand, six hundred twenty-one".