21164705136 has 120 divisors (see below), whose sum is σ = 62034873264. Its totient is φ = 6984921600.

The previous prime is 21164705129. The next prime is 21164705143. The reversal of 21164705136 is 63150746112.

21164705136 is a `hidden beast` number, since 2 + 1 + 1 + 647 + 0 + 5 + 1 + 3 + 6 = 666.

It is an interprime number because it is at equal distance from previous prime (21164705129) and next prime (21164705143).

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

It is a self number, because there is not a number n which added to its sum of digits gives 21164705136.

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 23 ways as a sum of consecutive naturals, for example, 365740 + ... + 419636.

Almost surely, 2^21164705136 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 21164705136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31017436632).

21164705136 is an abundant number, since it is smaller than the sum of its proper divisors (40870168128).

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

21164705136 is a wasteful number, since it uses less digits than its factorization.

21164705136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54021 (or 54003 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The spelling of 21164705136 in words is "twenty-one billion, one hundred sixty-four million, seven hundred five thousand, one hundred thirty-six".