72540428 has 24 divisors (see below), whose sum is σ = 135731232. Its totient is φ = 33801984.

The previous prime is 72540421. The next prime is 72540443. The reversal of 72540428 is 82404527.

It is a super-2 number, since 2×72540428² = 10524227388846368, which contains 22 as substring.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 72540394 and 72540403.

It is not an unprimeable number, because it can be changed into a prime (72540421) 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, 1826 + ... + 12182.

It is an arithmetic number, because the mean of its divisors is an integer number (5655468).

Almost surely, 2^72540428 is an apocalyptic number.

It is an amenable number.

72540428 is a deficient number, since it is larger than the sum of its proper divisors (63190804).

72540428 is a wasteful number, since it uses less digits than its factorization.

72540428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10481 (or 10479 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 32.

The square root of 72540428 is about 8517.0668660050. The cubic root of 72540428 is about 417.0550374289.

The spelling of 72540428 in words is "seventy-two million, five hundred forty thousand, four hundred twenty-eight".