21540321404 has 36 divisors (see below), whose sum is σ = 43864170336. Its totient is φ = 9228570624.

The previous prime is 21540321391. The next prime is 21540321421. The reversal of 21540321404 is 40412304512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 651644 + ... + 683900.

It is an arithmetic number, because the mean of its divisors is an integer number (1218449176).

Almost surely, 2^21540321404 is an apocalyptic number.

It is an amenable number.

21540321404 is an abundant number, since it is smaller than the sum of its proper divisors (22323848932).

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

21540321404 is a wasteful number, since it uses less digits than its factorization.

21540321404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35682 (or 35673 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 26.

Adding to 21540321404 its reverse (40412304512), we get a palindrome (61952625916).

The spelling of 21540321404 in words is "twenty-one billion, five hundred forty million, three hundred twenty-one thousand, four hundred four".