72664840 has 64 divisors (see below), whose sum is σ = 169646400. Its totient is φ = 27992832.

The previous prime is 72664799. The next prime is 72664841. The reversal of 72664840 is 4846627.

It is a self number, because there is not a number n which added to its sum of digits gives 72664840.

It is not an unprimeable number, because it can be changed into a prime (72664841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 142506 + ... + 143014.

It is an arithmetic number, because the mean of its divisors is an integer number (2650725).

Almost surely, 2^72664840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72664840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84823200).

72664840 is an abundant number, since it is smaller than the sum of its proper divisors (96981560).

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

72664840 is a wasteful number, since it uses less digits than its factorization.

72664840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646 (or 642 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 37.

The square root of 72664840 is about 8524.3674252111. The cubic root of 72664840 is about 417.2933276158.

The spelling of 72664840 in words is "seventy-two million, six hundred sixty-four thousand, eight hundred forty".