21998792660 has 24 divisors (see below), whose sum is σ = 49751116296. Its totient is φ = 8122631040.

The previous prime is 21998792603. The next prime is 21998792677. The reversal of 21998792660 is 6629789912.

It can be written as a sum of positive squares in 4 ways, for example, as 285001924 + 21713790736 = 16882^2 + 147356^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21998792660.

It is a congruent number.

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, 42305111 + ... + 42305630.

It is an arithmetic number, because the mean of its divisors is an integer number (2072963179).

Almost surely, 2^21998792660 is an apocalyptic number.

21998792660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21998792660 is an abundant number, since it is smaller than the sum of its proper divisors (27752323636).

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

21998792660 is a wasteful number, since it uses less digits than its factorization.

21998792660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84610763 (or 84610761 counting only the distinct ones).

The product of its (nonzero) digits is 5878656, while the sum is 59.

The spelling of 21998792660 in words is "twenty-one billion, nine hundred ninety-eight million, seven hundred ninety-two thousand, six hundred sixty".