79955021 has 4 divisors (see below), whose sum is σ = 84163200. Its totient is φ = 75746844.

The previous prime is 79955003. The next prime is 79955023. The reversal of 79955021 is 12055997.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 79955021 - 2¹⁰ = 79953997 is a prime.

It is a super-2 number, since 2×79955021² = 12785610766220882, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79955023) 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, 2104061 + ... + 2104098.

It is an arithmetic number, because the mean of its divisors is an integer number (21040800).

Almost surely, 2^79955021 is an apocalyptic number.

It is an amenable number.

79955021 is a deficient number, since it is larger than the sum of its proper divisors (4208179).

79955021 is a wasteful number, since it uses less digits than its factorization.

79955021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4208178.

The product of its (nonzero) digits is 28350, while the sum is 38.

The square root of 79955021 is about 8941.7571539379. The cubic root of 79955021 is about 430.8061692691.

The spelling of 79955021 in words is "seventy-nine million, nine hundred fifty-five thousand, twenty-one".