20557661930 has 48 divisors (see below), whose sum is σ = 40100167800. Its totient is φ = 7584655104.

The previous prime is 20557661921. The next prime is 20557661959. The reversal of 20557661930 is 3916675502.

It can be written as a sum of positive squares in 12 ways, for example, as 4249605721 + 16308056209 = 65189^2 + 127703^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2613884 + ... + 2621736.

Almost surely, 2^20557661930 is an apocalyptic number.

20557661930 is a deficient number, since it is larger than the sum of its proper divisors (19542505870).

20557661930 is a wasteful number, since it uses less digits than its factorization.

20557661930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9435 (or 9422 counting only the distinct ones).

The product of its (nonzero) digits is 340200, while the sum is 44.

The spelling of 20557661930 in words is "twenty billion, five hundred fifty-seven million, six hundred sixty-one thousand, nine hundred thirty".