82157720 has 16 divisors (see below), whose sum is σ = 184854960. Its totient is φ = 32863072.

The previous prime is 82157717. The next prime is 82157731. The reversal of 82157720 is 2775128.

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 3 ways as a sum of consecutive naturals, for example, 1026932 + ... + 1027011.

It is an arithmetic number, because the mean of its divisors is an integer number (11553435).

Almost surely, 2^82157720 is an apocalyptic number.

It is an amenable number.

82157720 is an abundant number, since it is smaller than the sum of its proper divisors (102697240).

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

82157720 is a wasteful number, since it uses less digits than its factorization.

82157720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2053954 (or 2053950 counting only the distinct ones).

The product of its (nonzero) digits is 7840, while the sum is 32.

The square root of 82157720 is about 9064.0895847294. The cubic root of 82157720 is about 434.7265114929.

The spelling of 82157720 in words is "eighty-two million, one hundred fifty-seven thousand, seven hundred twenty".