21213259164 has 36 divisors (see below), whose sum is σ = 53661928320. Its totient is φ = 7065874560.

The previous prime is 21213259163. The next prime is 21213259181. The reversal of 21213259164 is 46195231212.

21213259164 is a `hidden beast` number, since 2 + 1 + 2 + 1 + 3 + 2 + 591 + 64 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213259163) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 167484 + ... + 265475.

It is an arithmetic number, because the mean of its divisors is an integer number (1490609120).

Almost surely, 2^21213259164 is an apocalyptic number.

It is an amenable number.

21213259164 is an abundant number, since it is smaller than the sum of its proper divisors (32448669156).

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

21213259164 is a wasteful number, since it uses less digits than its factorization.

21213259164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434330 (or 434325 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The spelling of 21213259164 in words is "twenty-one billion, two hundred thirteen million, two hundred fifty-nine thousand, one hundred sixty-four".