72661665600 has 504 divisors, whose sum is σ = 275114662368. Its totient is φ = 18849024000.

The previous prime is 72661665569. The next prime is 72661665613. The reversal of 72661665600 is 656616627.

72661665600 is a `hidden beast` number, since 7 + 26 + 6 + 1 + 66 + 560 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 14383075 + ... + 14388125.

Almost surely, 2^72661665600 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 72661665600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137557331184).

72661665600 is an abundant number, since it is smaller than the sum of its proper divisors (202452996768).

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

72661665600 is a wasteful number, since it uses less digits than its factorization.

72661665600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5125 (or 5098 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The spelling of 72661665600 in words is "seventy-two billion, six hundred sixty-one million, six hundred sixty-five thousand, six hundred".