72157920 has 48 divisors (see below), whose sum is σ = 227298960. Its totient is φ = 19241984.

The previous prime is 72157901. The next prime is 72157927. The reversal of 72157920 is 2975127.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72157927) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74685 + ... + 75644.

It is an arithmetic number, because the mean of its divisors is an integer number (4735395).

Almost surely, 2^72157920 is an apocalyptic number.

It is an amenable number.

72157920 is an abundant number, since it is smaller than the sum of its proper divisors (155141040).

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

72157920 is a wasteful number, since it uses less digits than its factorization.

72157920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150347 (or 150339 counting only the distinct ones).

The product of its (nonzero) digits is 8820, while the sum is 33.

The square root of 72157920 is about 8494.5818025374. The cubic root of 72157920 is about 416.3206969892.

The spelling of 72157920 in words is "seventy-two million, one hundred fifty-seven thousand, nine hundred twenty".