72641664 has 64 divisors (see below), whose sum is σ = 214404000. Its totient is φ = 24212736.

The previous prime is 72641573. The next prime is 72641669. The reversal of 72641664 is 46614627.

72641664 is a `hidden beast` number, since 7 + 2 + 641 + 6 + 6 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×72641664² = 10553622697377792, which contains 22 as substring.

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 not an unprimeable number, because it can be changed into a prime (72641669) 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, 7054 + ... + 13965.

Almost surely, 2^72641664 is an apocalyptic number.

It is an amenable number.

72641664 is an abundant number, since it is smaller than the sum of its proper divisors (141762336).

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

72641664 is a wasteful number, since it uses less digits than its factorization.

72641664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21042 (or 21024 counting only the distinct ones).

The product of its digits is 48384, while the sum is 36.

The square root of 72641664 is about 8523.0079197429. The cubic root of 72641664 is about 417.2489585256.

The spelling of 72641664 in words is "seventy-two million, six hundred forty-one thousand, six hundred sixty-four".