21253630244 has 36 divisors (see below), whose sum is σ = 47199625200. Its totient is φ = 8280634320.

The previous prime is 21253630127. The next prime is 21253630267. The reversal of 21253630244 is 44203635212.

It is a self number, because there is not a number n which added to its sum of digits gives 21253630244.

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, 4926794 + ... + 4931105.

It is an arithmetic number, because the mean of its divisors is an integer number (1311100700).

Almost surely, 2^21253630244 is an apocalyptic number.

It is an amenable number.

21253630244 is an abundant number, since it is smaller than the sum of its proper divisors (25945994956).

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

21253630244 is a wasteful number, since it uses less digits than its factorization.

21253630244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9857928 (or 9857919 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 32.

The spelling of 21253630244 in words is "twenty-one billion, two hundred fifty-three million, six hundred thirty thousand, two hundred forty-four".