21317313659388 has 24 divisors (see below), whose sum is σ = 49740983295360. Its totient is φ = 7105687683120.

The previous prime is 21317313659381. The next prime is 21317313659401. The reversal of 21317313659388 is 88395631371312.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21317313659381) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9374448 + ... + 11424311.

It is an arithmetic number, because the mean of its divisors is an integer number (2072540970640).

Almost surely, 2^{21317313659388} is an apocalyptic number.

It is an amenable number.

21317313659388 is an abundant number, since it is smaller than the sum of its proper divisors (28423669635972).

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

21317313659388 is a wasteful number, since it uses less digits than its factorization.

21317313659388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20884177 (or 20884175 counting only the distinct ones).

The product of its digits is 19595520, while the sum is 60.

The spelling of 21317313659388 in words is "twenty-one trillion, three hundred seventeen billion, three hundred thirteen million, six hundred fifty-nine thousand, three hundred eighty-eight".