72731520 has 320 divisors, whose sum is σ = 275473440. Its totient is φ = 18247680.

The previous prime is 72731501. The next prime is 72731521. The reversal of 72731520 is 2513727.

72731520 is a `hidden beast` number, since 72 + 73 + 1 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (320).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72731521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1192290 + ... + 1192350.

Almost surely, 2^72731520 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 72731520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137736720).

72731520 is an abundant number, since it is smaller than the sum of its proper divisors (202741920).

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

72731520 is a wasteful number, since it uses less digits than its factorization.

72731520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115 (or 94 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 27.

The square root of 72731520 is about 8528.2776690256. The cubic root of 72731520 is about 417.4209299624.

The spelling of 72731520 in words is "seventy-two million, seven hundred thirty-one thousand, five hundred twenty".