21213633264 has 80 divisors (see below), whose sum is σ = 55664353920. Its totient is φ = 6960096000.

The previous prime is 21213633191. The next prime is 21213633299. The reversal of 21213633264 is 46233631212.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6523639 + ... + 6526889.

It is an arithmetic number, because the mean of its divisors is an integer number (695804424).

Almost surely, 2^21213633264 is an apocalyptic number.

21213633264 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21213633264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27832176960).

21213633264 is an abundant number, since it is smaller than the sum of its proper divisors (34450720656).

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

21213633264 is a wasteful number, since it uses less digits than its factorization.

21213633264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5358 (or 5352 counting only the distinct ones).

The product of its digits is 31104, while the sum is 33.

The spelling of 21213633264 in words is "twenty-one billion, two hundred thirteen million, six hundred thirty-three thousand, two hundred sixty-four".