21218752072 has 32 divisors (see below), whose sum is σ = 45603717120. Its totient is φ = 9066758400.

The previous prime is 21218752069. The next prime is 21218752129. The reversal of 21218752072 is 27025781212.

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 7 ways as a sum of consecutive naturals, for example, 543304 + ... + 581047.

It is an arithmetic number, because the mean of its divisors is an integer number (1425116160).

Almost surely, 2^21218752072 is an apocalyptic number.

It is an amenable number.

21218752072 is an abundant number, since it is smaller than the sum of its proper divisors (24384965048).

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

21218752072 is a wasteful number, since it uses less digits than its factorization.

21218752072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1124701 (or 1124697 counting only the distinct ones).

The product of its (nonzero) digits is 31360, while the sum is 37.

The spelling of 21218752072 in words is "twenty-one billion, two hundred eighteen million, seven hundred fifty-two thousand, seventy-two".