21646652832 has 144 divisors (see below), whose sum is σ = 70414868160. Its totient is φ = 6179198976.

The previous prime is 21646652831. The next prime is 21646652849. The reversal of 21646652832 is 23825664612.

21646652832 is a `hidden beast` number, since 2 + 1 + 64 + 66 + 528 + 3 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is not an unprimeable number, because it can be changed into a prime (21646652831) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2582344 + ... + 2590712.

It is an arithmetic number, because the mean of its divisors is an integer number (488992140).

Almost surely, 2^21646652832 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 21646652832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35207434080).

21646652832 is an abundant number, since it is smaller than the sum of its proper divisors (48768215328).

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

21646652832 is a wasteful number, since it uses less digits than its factorization.

21646652832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9675 (or 9664 counting only the distinct ones).

The product of its digits is 829440, while the sum is 45.

The spelling of 21646652832 in words is "twenty-one billion, six hundred forty-six million, six hundred fifty-two thousand, eight hundred thirty-two".