72156440 has 32 divisors (see below), whose sum is σ = 162600480. Its totient is φ = 28818432.

The previous prime is 72156439. The next prime is 72156443. The reversal of 72156440 is 4465127.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72156443) 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, 41672 + ... + 43368.

It is an arithmetic number, because the mean of its divisors is an integer number (5081265).

Almost surely, 2^72156440 is an apocalyptic number.

It is an amenable number.

72156440 is an abundant number, since it is smaller than the sum of its proper divisors (90444040).

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

72156440 is a wasteful number, since it uses less digits than its factorization.

72156440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2771 (or 2767 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 29.

The square root of 72156440 is about 8494.4946877375. The cubic root of 72156440 is about 416.3178506450.

The spelling of 72156440 in words is "seventy-two million, one hundred fifty-six thousand, four hundred forty".