21653745432012 has 96 divisors (see below), whose sum is σ = 56443226112000. Its totient is φ = 7178857430400.

The previous prime is 21653745432001. The next prime is 21653745432013. The reversal of 21653745432012 is 21023454735612.

21653745432012 is a `hidden beast` number, since 2 + 1 + 6 + 5 + 3 + 74 + 543 + 20 + 12 = 666.

It is not an unprimeable number, because it can be changed into a prime (21653745432013) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 120563437 + ... + 120742907.

It is an arithmetic number, because the mean of its divisors is an integer number (587950272000).

Almost surely, 2^{21653745432012} 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 21653745432012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28221613056000).

21653745432012 is an abundant number, since it is smaller than the sum of its proper divisors (34789480679988).

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

21653745432012 is a wasteful number, since it uses less digits than its factorization.

21653745432012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185524 (or 185516 counting only the distinct ones).

The product of its (nonzero) digits is 1209600, while the sum is 45.

The spelling of 21653745432012 in words is "twenty-one trillion, six hundred fifty-three billion, seven hundred forty-five million, four hundred thirty-two thousand, twelve".