21368659716 has 18 divisors (see below), whose sum is σ = 54015223262. Its totient is φ = 7122886560.

The previous prime is 21368659699. The next prime is 21368659729. The reversal of 21368659716 is 61795686312.

21368659716 is a `hidden beast` number, since 2 + 1 + 36 + 8 + 6 + 597 + 16 = 666.

It can be written as a sum of positive squares in only one way, i.e., 21229655616 + 139004100 = 145704^2 + 11790^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 296786905 + ... + 296786976.

Almost surely, 2^21368659716 is an apocalyptic number.

It is an amenable number.

21368659716 is an abundant number, since it is smaller than the sum of its proper divisors (32646563546).

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

21368659716 is a wasteful number, since it uses less digits than its factorization.

21368659716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 593573891 (or 593573886 counting only the distinct ones).

The product of its digits is 3265920, while the sum is 54.

The spelling of 21368659716 in words is "twenty-one billion, three hundred sixty-eight million, six hundred fifty-nine thousand, seven hundred sixteen".