21020804193624 has 256 divisors, whose sum is σ = 54209046528000. Its totient is φ = 6790787538432.

The previous prime is 21020804193611. The next prime is 21020804193661. The reversal of 21020804193624 is 42639140802012.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 15377324989 + ... + 15377326355.

It is an arithmetic number, because the mean of its divisors is an integer number (211754088000).

Almost surely, 2^{21020804193624} is an apocalyptic number.

21020804193624 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21020804193624 is an abundant number, since it is smaller than the sum of its proper divisors (33188242334376).

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

21020804193624 is a wasteful number, since it uses less digits than its factorization.

21020804193624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2214 (or 2210 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 42.

Adding to 21020804193624 its reverse (42639140802012), we get a palindrome (63659944995636).

The spelling of 21020804193624 in words is "twenty-one trillion, twenty billion, eight hundred four million, one hundred ninety-three thousand, six hundred twenty-four".