21136205264 has 40 divisors (see below), whose sum is σ = 45642435840. Its totient is φ = 9422949888.

The previous prime is 21136205243. The next prime is 21136205269. The reversal of 21136205264 is 46250263112.

It is a self number, because there is not a number n which added to its sum of digits gives 21136205264.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21136205269) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2039744 + ... + 2050079.

It is an arithmetic number, because the mean of its divisors is an integer number (1141060896).

Almost surely, 2^21136205264 is an apocalyptic number.

It is an amenable number.

21136205264 is an abundant number, since it is smaller than the sum of its proper divisors (24506230576).

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

21136205264 is a wasteful number, since it uses less digits than its factorization.

21136205264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4089867 (or 4089861 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 32.

Adding to 21136205264 its reverse (46250263112), we get a palindrome (67386468376).

The spelling of 21136205264 in words is "twenty-one billion, one hundred thirty-six million, two hundred five thousand, two hundred sixty-four".