21086560168 has 8 divisors (see below), whose sum is σ = 39537300330. Its totient is φ = 10543280080.

The previous prime is 21086560139. The next prime is 21086560169. The reversal of 21086560168 is 86106568012.

It can be written as a sum of positive squares in only one way, i.e., 13833993924 + 7252566244 = 117618^2 + 85162^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (21086560169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1317910003 + ... + 1317910018.

Almost surely, 2^21086560168 is an apocalyptic number.

It is an amenable number.

21086560168 is a deficient number, since it is larger than the sum of its proper divisors (18450740162).

21086560168 is a wasteful number, since it uses less digits than its factorization.

21086560168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2635820027 (or 2635820023 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 43.

The spelling of 21086560168 in words is "twenty-one billion, eighty-six million, five hundred sixty thousand, one hundred sixty-eight".