72235728 has 30 divisors (see below), whose sum is σ = 202160114. Its totient is φ = 24078528.

The previous prime is 72235711. The next prime is 72235733. The reversal of 72235728 is 82753227.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 63872064 + 8363664 = 7992^2 + 2892^2 .

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 72235692 and 72235701.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 250675 + ... + 250962.

Almost surely, 2^72235728 is an apocalyptic number.

It is an amenable number.

72235728 is an abundant number, since it is smaller than the sum of its proper divisors (129924386).

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

72235728 is a wasteful number, since it uses less digits than its factorization.

72235728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 501651 (or 501642 counting only the distinct ones).

The product of its digits is 47040, while the sum is 36.

The square root of 72235728 is about 8499.1604291247. The cubic root of 72235728 is about 416.4702829926.

The spelling of 72235728 in words is "seventy-two million, two hundred thirty-five thousand, seven hundred twenty-eight".