21359832921 has 48 divisors (see below), whose sum is σ = 36686633984. Its totient is φ = 12165563664.

The previous prime is 21359832919. The next prime is 21359832979. The reversal of 21359832921 is 12923895312.

21359832921 is a `hidden beast` number, since 2 + 1 + 3 + 598 + 32 + 9 + 21 = 666.

It is not a de Polignac number, because 21359832921 - 2¹ = 21359832919 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21359837921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 501756 + ... + 542658.

Almost surely, 2^21359832921 is an apocalyptic number.

21359832921 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21359832921 is a deficient number, since it is larger than the sum of its proper divisors (15326801063).

21359832921 is an equidigital number, since it uses as much as digits as its factorization.

21359832921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41232 (or 41220 counting only the distinct ones).

The product of its digits is 233280, while the sum is 45.

The spelling of 21359832921 in words is "twenty-one billion, three hundred fifty-nine million, eight hundred thirty-two thousand, nine hundred twenty-one".