79172840 has 16 divisors (see below), whose sum is σ = 178138980. Its totient is φ = 31669120.

The previous prime is 79172803. The next prime is 79172851. The reversal of 79172840 is 4827197.

It can be written as a sum of positive squares in 2 ways, for example, as 75307684 + 3865156 = 8678^2 + 1966^2 .

It is a junction number, because it is equal to n+sod(n) for n = 79172794 and 79172803.

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 3 ways as a sum of consecutive naturals, for example, 989621 + ... + 989700.

Almost surely, 2^79172840 is an apocalyptic number.

It is an amenable number.

79172840 is an abundant number, since it is smaller than the sum of its proper divisors (98966140).

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

79172840 is a wasteful number, since it uses less digits than its factorization.

79172840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1979332 (or 1979328 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 79172840 is about 8897.9121146480. The cubic root of 79172840 is about 429.3967383392.

The spelling of 79172840 in words is "seventy-nine million, one hundred seventy-two thousand, eight hundred forty".