21532917564 has 144 divisors (see below), whose sum is σ = 57088245760. Its totient is φ = 6835570560.

The previous prime is 21532917563. The next prime is 21532917599. The reversal of 21532917564 is 46571923512.

21532917564 is a `hidden beast` number, since 2 + 1 + 53 + 29 + 17 + 564 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

Its product of digits (453600) is a multiple of the sum of its prime factors (1400).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21532917563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 19700202 + ... + 19701294.

Almost surely, 2^21532917564 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 21532917564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28544122880).

21532917564 is an abundant number, since it is smaller than the sum of its proper divisors (35555328196).

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

21532917564 is a wasteful number, since it uses less digits than its factorization.

21532917564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1400 (or 1395 counting only the distinct ones).

The product of its digits is 453600, while the sum is 45.

The spelling of 21532917564 in words is "twenty-one billion, five hundred thirty-two million, nine hundred seventeen thousand, five hundred sixty-four".