21655250244 has 72 divisors (see below), whose sum is σ = 55398470400. Its totient is φ = 7131866112.

The previous prime is 21655250137. The next prime is 21655250257. The reversal of 21655250244 is 44205255612.

21655250244 is a `hidden beast` number, since 2 + 1 + 65 + 52 + 502 + 44 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21655250199 and 21655250208.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1658389 + ... + 1671395.

It is an arithmetic number, because the mean of its divisors is an integer number (769423200).

Almost surely, 2^21655250244 is an apocalyptic number.

It is an amenable number.

21655250244 is an abundant number, since it is smaller than the sum of its proper divisors (33743220156).

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

21655250244 is a wasteful number, since it uses less digits than its factorization.

21655250244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13569 (or 13564 counting only the distinct ones).

The product of its (nonzero) digits is 96000, while the sum is 36.

The spelling of 21655250244 in words is "twenty-one billion, six hundred fifty-five million, two hundred fifty thousand, two hundred forty-four".