21233637664 has 48 divisors (see below), whose sum is σ = 42179833080. Its totient is φ = 10521722880.

The previous prime is 21233637613. The next prime is 21233637679. The reversal of 21233637664 is 46673633212.

It can be written as a sum of positive squares in 4 ways, for example, as 13108418064 + 8125219600 = 114492^2 + 90140^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21233637664.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1654954 + ... + 1667734.

Almost surely, 2^21233637664 is an apocalyptic number.

It is an amenable number.

21233637664 is a deficient number, since it is larger than the sum of its proper divisors (20946195416).

21233637664 is a wasteful number, since it uses less digits than its factorization.

21233637664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13253 (or 13245 counting only the distinct ones).

The product of its digits is 653184, while the sum is 43.

It can be divided in two parts, 212336 and 37664, that added together give a square (250000 = 500²).

The spelling of 21233637664 in words is "twenty-one billion, two hundred thirty-three million, six hundred thirty-seven thousand, six hundred sixty-four".