21568157188 has 12 divisors (see below), whose sum is σ = 37797515980. Its totient is φ = 10768866912.

The previous prime is 21568157183. The next prime is 21568157189. The reversal of 21568157188 is 88175186512.

It can be written as a sum of positive squares in 2 ways, for example, as 1995587584 + 19572569604 = 44672^2 + 139902^2 .

It is not an unprimeable number, because it can be changed into a prime (21568157183) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3799731 + ... + 3805402.

Almost surely, 2^21568157188 is an apocalyptic number.

It is an amenable number.

21568157188 is a deficient number, since it is larger than the sum of its proper divisors (16229358792).

21568157188 is a wasteful number, since it uses less digits than its factorization.

21568157188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7605846 (or 7605844 counting only the distinct ones).

The product of its digits is 1075200, while the sum is 52.

The spelling of 21568157188 in words is "twenty-one billion, five hundred sixty-eight million, one hundred fifty-seven thousand, one hundred eighty-eight".