22721978660 has 24 divisors (see below), whose sum is σ = 50522988600. Its totient is φ = 8554156544.

The previous prime is 22721978639. The next prime is 22721978693. The reversal of 22721978660 is 6687912722.

It can be written as a sum of positive squares in 4 ways, for example, as 4121383204 + 18600595456 = 64198^2 + 136384^2 .

It is a junction number, because it is equal to n+sod(n) for n = 22721978599 and 22721978608.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33414335 + ... + 33415014.

It is an arithmetic number, because the mean of its divisors is an integer number (2105124525).

Almost surely, 2^22721978660 is an apocalyptic number.

22721978660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

22721978660 is an abundant number, since it is smaller than the sum of its proper divisors (27801009940).

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

22721978660 is a wasteful number, since it uses less digits than its factorization.

22721978660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66829375 (or 66829373 counting only the distinct ones).

The product of its (nonzero) digits is 1016064, while the sum is 50.

The spelling of 22721978660 in words is "twenty-two billion, seven hundred twenty-one million, nine hundred seventy-eight thousand, six hundred sixty".