21164305437 has 48 divisors (see below), whose sum is σ = 34096308480. Its totient is φ = 12540336000.

The previous prime is 21164305433. The next prime is 21164305451. The reversal of 21164305437 is 73450346112.

21164305437 is a `hidden beast` number, since 2 + 1 + 1 + 643 + 0 + 5 + 4 + 3 + 7 = 666.

It is not a de Polignac number, because 21164305437 - 2² = 21164305433 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21164305433) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5716687 + ... + 5720387.

It is an arithmetic number, because the mean of its divisors is an integer number (710339760).

Almost surely, 2^21164305437 is an apocalyptic number.

It is an amenable number.

21164305437 is a deficient number, since it is larger than the sum of its proper divisors (12932003043).

21164305437 is a wasteful number, since it uses less digits than its factorization.

21164305437 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4994 (or 4991 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The spelling of 21164305437 in words is "twenty-one billion, one hundred sixty-four million, three hundred five thousand, four hundred thirty-seven".