21640162540344 has 32 divisors (see below), whose sum is σ = 56947796160000. Its totient is φ = 6833735538912.

The previous prime is 21640162540319. The next prime is 21640162540349. The reversal of 21640162540344 is 44304526104612.

It is a junction number, because it is equal to n+sod(n) for n = 21640162540296 and 21640162540305.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21640162540349) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23728247944 + ... + 23728248855.

It is an arithmetic number, because the mean of its divisors is an integer number (1779618630000).

Almost surely, 2^{21640162540344} is an apocalyptic number.

21640162540344 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21640162540344 is an abundant number, since it is smaller than the sum of its proper divisors (35307633619656).

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

21640162540344 is a wasteful number, since it uses less digits than its factorization.

21640162540344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47456496827 (or 47456496823 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 42.

Adding to 21640162540344 its reverse (44304526104612), we get a palindrome (65944688644956).

The spelling of 21640162540344 in words is "twenty-one trillion, six hundred forty billion, one hundred sixty-two million, five hundred forty thousand, three hundred forty-four".