21666035125631 has 8 divisors (see below), whose sum is σ = 23337959767584. Its totient is φ = 19994868563040.

The previous prime is 21666035125627. The next prime is 21666035125661. The reversal of 21666035125631 is 13652153066612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21666035125631 - 2² = 21666035125627 is a prime.

It is a super-2 number, since 2×21666035125631² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21666035125601) 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, 189460475 + ... + 189574796.

It is an arithmetic number, because the mean of its divisors is an integer number (2917244970948).

Almost surely, 2^{21666035125631} is an apocalyptic number.

21666035125631 is a deficient number, since it is larger than the sum of its proper divisors (1671924641953).

21666035125631 is a wasteful number, since it uses less digits than its factorization.

21666035125631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 379039681.

The product of its (nonzero) digits is 1166400, while the sum is 47.

The spelling of 21666035125631 in words is "twenty-one trillion, six hundred sixty-six billion, thirty-five million, one hundred twenty-five thousand, six hundred thirty-one".