21205335996 has 36 divisors (see below), whose sum is σ = 57725638152. Its totient is φ = 6524718624.

The previous prime is 21205335973. The next prime is 21205336027. The reversal of 21205335996 is 69953350212.

21205335996 is a `hidden beast` number, since 2 + 1 + 2 + 0 + 53 + 3 + 599 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

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, 22654806 + ... + 22655741.

Almost surely, 2^21205335996 is an apocalyptic number.

21205335996 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21205335996 is an abundant number, since it is smaller than the sum of its proper divisors (36520302156).

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

21205335996 is a wasteful number, since it uses less digits than its factorization.

21205335996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45310570 (or 45310565 counting only the distinct ones).

The product of its (nonzero) digits is 437400, while the sum is 45.

The spelling of 21205335996 in words is "twenty-one billion, two hundred five million, three hundred thirty-five thousand, nine hundred ninety-six".