80815720 has 16 divisors (see below), whose sum is σ = 181835460. Its totient is φ = 32326272.

The previous prime is 80815711. The next prime is 80815741. The reversal of 80815720 is 2751808.

It can be written as a sum of positive squares in 2 ways, for example, as 78747876 + 2067844 = 8874^2 + 1438^2 .

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, 1010157 + ... + 1010236.

Almost surely, 2^80815720 is an apocalyptic number.

It is an amenable number.

80815720 is an abundant number, since it is smaller than the sum of its proper divisors (101019740).

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

80815720 is a wasteful number, since it uses less digits than its factorization.

80815720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2020404 (or 2020400 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 31.

The square root of 80815720 is about 8989.7563926950. The cubic root of 80815720 is about 432.3465012656.

The spelling of 80815720 in words is "eighty million, eight hundred fifteen thousand, seven hundred twenty".