21117357351 has 12 divisors (see below), whose sum is σ = 30505525960. Its totient is φ = 14077002960.

The previous prime is 21117357341. The next prime is 21117357353. The reversal of 21117357351 is 15375371112.

21117357351 is a `hidden beast` number, since 2 + 1 + 11 + 73 + 573 + 5 + 1 = 666.

It is not a de Polignac number, because 21117357351 - 2⁷ = 21117357223 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21117357353) 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, 12096 + ... + 205866.

Almost surely, 2^21117357351 is an apocalyptic number.

21117357351 is a deficient number, since it is larger than the sum of its proper divisors (9388168609).

21117357351 is a wasteful number, since it uses less digits than its factorization.

21117357351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205886 (or 205883 counting only the distinct ones).

The product of its digits is 22050, while the sum is 36.

The spelling of 21117357351 in words is "twenty-one billion, one hundred seventeen million, three hundred fifty-seven thousand, three hundred fifty-one".