21317606361 has 12 divisors (see below), whose sum is σ = 30836668720. Its totient is φ = 14191166520.

The previous prime is 21317606357. The next prime is 21317606369. The reversal of 21317606361 is 16360671312.

21317606361 is a `hidden beast` number, since 2 + 1 + 3 + 17 + 6 + 0 + 636 + 1 = 666.

It is not a de Polignac number, because 21317606361 - 2² = 21317606357 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21317606369) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1707691 + ... + 1720128.

Almost surely, 2^21317606361 is an apocalyptic number.

It is an amenable number.

21317606361 is a deficient number, since it is larger than the sum of its proper divisors (9519062359).

21317606361 is a wasteful number, since it uses less digits than its factorization.

21317606361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3428516 (or 3428513 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 36.

The spelling of 21317606361 in words is "twenty-one billion, three hundred seventeen million, six hundred six thousand, three hundred sixty-one".