79721998 has 16 divisors (see below), whose sum is σ = 123023376. Its totient is φ = 38730240.

The previous prime is 79721977. The next prime is 79722023. The reversal of 79721998 is 89912797.

It is a super-2 number, since 2×79721998² = 12711193930224008, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6190 + ... + 14062.

It is an arithmetic number, because the mean of its divisors is an integer number (7688961).

Almost surely, 2^79721998 is an apocalyptic number.

79721998 is a deficient number, since it is larger than the sum of its proper divisors (43301378).

79721998 is a wasteful number, since it uses less digits than its factorization.

79721998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8019.

The product of its digits is 571536, while the sum is 52.

The square root of 79721998 is about 8928.7176010892. The cubic root of 79721998 is about 430.3872444488.

The spelling of 79721998 in words is "seventy-nine million, seven hundred twenty-one thousand, nine hundred ninety-eight".