21108432690 has 96 divisors (see below), whose sum is σ = 55233472320. Its totient is φ = 5592984192.

The previous prime is 21108432677. The next prime is 21108432701. The reversal of 21108432690 is 9623480112.

21108432690 is a `hidden beast` number, since 211 + 0 + 8 + 432 + 6 + 9 + 0 = 666.

It is a super-2 number, since 2×21108432690² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11305137 + ... + 11307003.

It is an arithmetic number, because the mean of its divisors is an integer number (575348670).

Almost surely, 2^21108432690 is an apocalyptic number.

21108432690 is an abundant number, since it is smaller than the sum of its proper divisors (34125039630).

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

21108432690 is a wasteful number, since it uses less digits than its factorization.

21108432690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2616 (or 2613 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The spelling of 21108432690 in words is "twenty-one billion, one hundred eight million, four hundred thirty-two thousand, six hundred ninety".