72921320 has 16 divisors (see below), whose sum is σ = 164073060. Its totient is φ = 29168512.

The previous prime is 72921301. The next prime is 72921353. The reversal of 72921320 is 2312927.

It can be written as a sum of positive squares in 2 ways, for example, as 67930564 + 4990756 = 8242^2 + 2234^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 72921320.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 911477 + ... + 911556.

Almost surely, 2^72921320 is an apocalyptic number.

It is an amenable number.

72921320 is an abundant number, since it is smaller than the sum of its proper divisors (91151740).

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

72921320 is a wasteful number, since it uses less digits than its factorization.

72921320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1823044 (or 1823040 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 72921320 is about 8539.3981052531. The cubic root of 72921320 is about 417.7837147900.

The spelling of 72921320 in words is "seventy-two million, nine hundred twenty-one thousand, three hundred twenty".