72128780 has 24 divisors (see below), whose sum is σ = 151647552. Its totient is φ = 28817792.

The previous prime is 72128753. The next prime is 72128801. The reversal of 72128780 is 8782127.

It is a self number, because there is not a number n which added to its sum of digits gives 72128780.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22349 + ... + 25371.

It is an arithmetic number, because the mean of its divisors is an integer number (6318648).

Almost surely, 2^72128780 is an apocalyptic number.

It is an amenable number.

72128780 is an abundant number, since it is smaller than the sum of its proper divisors (79518772).

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

72128780 is a wasteful number, since it uses less digits than its factorization.

72128780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4225 (or 4223 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 35.

The square root of 72128780 is about 8492.8664183537. The cubic root of 72128780 is about 416.2646476162.

The spelling of 72128780 in words is "seventy-two million, one hundred twenty-eight thousand, seven hundred eighty".