21221603653164 has 96 divisors (see below), whose sum is σ = 51498284302080. Its totient is φ = 6793463400192.

The previous prime is 21221603653111. The next prime is 21221603653189. The reversal of 21221603653164 is 46135630612212.

It is a super-2 number, since 2×21221603653164² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 270551319 + ... + 270629745.

It is an arithmetic number, because the mean of its divisors is an integer number (536440461480).

Almost surely, 2^{21221603653164} 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 21221603653164, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25749142151040).

21221603653164 is an abundant number, since it is smaller than the sum of its proper divisors (30276680648916).

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

21221603653164 is a wasteful number, since it uses less digits than its factorization.

21221603653164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82607 (or 82605 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 42.

The spelling of 21221603653164 in words is "twenty-one trillion, two hundred twenty-one billion, six hundred three million, six hundred fifty-three thousand, one hundred sixty-four".