21656674228 has 24 divisors (see below), whose sum is σ = 43572719232. Its totient is φ = 9225852384.

The previous prime is 21656674189. The next prime is 21656674313. The reversal of 21656674228 is 82247665612.

It is a hoax number, since the sum of its digits (49) coincides with the sum of the digits of its distinct prime factors.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 2311051 + ... + 2320402.

It is an arithmetic number, because the mean of its divisors is an integer number (1815529968).

Almost surely, 2^21656674228 is an apocalyptic number.

21656674228 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21656674228 is an abundant number, since it is smaller than the sum of its proper divisors (21916045004).

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

21656674228 is a wasteful number, since it uses less digits than its factorization.

21656674228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4631631 (or 4631629 counting only the distinct ones).

The product of its digits is 1935360, while the sum is 49.

The spelling of 21656674228 in words is "twenty-one billion, six hundred fifty-six million, six hundred seventy-four thousand, two hundred twenty-eight".