72665721216 has 128 divisors (see below), whose sum is σ = 233961724800. Its totient is φ = 22019904000.

The previous prime is 72665721169. The next prime is 72665721277. The reversal of 72665721216 is 61212756627.

72665721216 is a `hidden beast` number, since 7 + 2 + 66 + 572 + 1 + 2 + 16 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

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, 917710 + ... + 993741.

It is an arithmetic number, because the mean of its divisors is an integer number (1827825975).

Almost surely, 2^72665721216 is an apocalyptic number.

It is an amenable number.

72665721216 is an abundant number, since it is smaller than the sum of its proper divisors (161296003584).

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

72665721216 is a wasteful number, since it uses less digits than its factorization.

72665721216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1911485 (or 1911467 counting only the distinct ones).

The product of its digits is 423360, while the sum is 45.

It can be divided in two parts, 72665 and 721216, that added together give a square (793881 = 891²).

The spelling of 72665721216 in words is "seventy-two billion, six hundred sixty-five million, seven hundred twenty-one thousand, two hundred sixteen".