79721900 has 36 divisors (see below), whose sum is σ = 173457648. Its totient is φ = 31803840.

The previous prime is 79721881. The next prime is 79721903. The reversal of 79721900 is 912797.

It is a super-2 number, since 2×79721900² = 12711162679220000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (79721903) 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, 47882 + ... + 49518.

It is an arithmetic number, because the mean of its divisors is an integer number (4818268).

Almost surely, 2^79721900 is an apocalyptic number.

It is an amenable number.

79721900 is an abundant number, since it is smaller than the sum of its proper divisors (93735748).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

79721900 is a wasteful number, since it uses less digits than its factorization.

79721900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2138 (or 2131 counting only the distinct ones).

The product of its (nonzero) digits is 7938, while the sum is 35.

The square root of 79721900 is about 8928.7121131774. The cubic root of 79721900 is about 430.3870680945.

The spelling of 79721900 in words is "seventy-nine million, seven hundred twenty-one thousand, nine hundred".