21731645317608 has 32 divisors (see below), whose sum is σ = 60365681438400. Its totient is φ = 7243881772464.

The previous prime is 21731645317567. The next prime is 21731645317769. The reversal of 21731645317608 is 80671354613712.

21731645317608 is a `hidden beast` number, since 2 + 1 + 7 + 3 + 16 + 4 + 5 + 3 + 17 + 608 = 666.

It is a super-2 number, since 2×21731645317608² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50304734316 + ... + 50304734747.

It is an arithmetic number, because the mean of its divisors is an integer number (1886427544950).

Almost surely, 2^{21731645317608} is an apocalyptic number.

It is an amenable number.

21731645317608 is an abundant number, since it is smaller than the sum of its proper divisors (38634036120792).

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

21731645317608 is a wasteful number, since it uses less digits than its factorization.

21731645317608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100609469078 (or 100609469068 counting only the distinct ones).

The product of its (nonzero) digits is 5080320, while the sum is 54.

The spelling of 21731645317608 in words is "twenty-one trillion, seven hundred thirty-one billion, six hundred forty-five million, three hundred seventeen thousand, six hundred eight".