72656777520 has 80 divisors (see below), whose sum is σ = 250262241120. Its totient is φ = 19375140096.

The previous prime is 72656777497. The next prime is 72656777533. The reversal of 72656777520 is 2577765627.

It is a happy number.

72656777520 is a `hidden beast` number, since 7 + 2 + 6 + 567 + 7 + 75 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16816539 + ... + 16820858.

It is an arithmetic number, because the mean of its divisors is an integer number (3128278014).

Almost surely, 2^72656777520 is an apocalyptic number.

It is an amenable number.

72656777520 is an abundant number, since it is smaller than the sum of its proper divisors (177605463600).

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

72656777520 is a wasteful number, since it uses less digits than its factorization.

72656777520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33637419 (or 33637407 counting only the distinct ones).

The product of its (nonzero) digits is 8643600, while the sum is 54.

The spelling of 72656777520 in words is "seventy-two billion, six hundred fifty-six million, seven hundred seventy-seven thousand, five hundred twenty".