21364398636 has 48 divisors (see below), whose sum is σ = 56978874624. Its totient is φ = 6103348416.

The previous prime is 21364398577. The next prime is 21364398667. The reversal of 21364398636 is 63689346312.

It is a happy number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 1329546 + ... + 1345518.

It is an arithmetic number, because the mean of its divisors is an integer number (1187059888).

Almost surely, 2^21364398636 is an apocalyptic number.

It is an amenable number.

21364398636 is an abundant number, since it is smaller than the sum of its proper divisors (35614475988).

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

21364398636 is a wasteful number, since it uses less digits than its factorization.

21364398636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31910 (or 31908 counting only the distinct ones).

The product of its digits is 3359232, while the sum is 51.

The spelling of 21364398636 in words is "twenty-one billion, three hundred sixty-four million, three hundred ninety-eight thousand, six hundred thirty-six".