21097519686 has 40 divisors (see below), whose sum is σ = 47307179304. Its totient is φ = 7027581600.

The previous prime is 21097519627. The next prime is 21097519693. The reversal of 21097519686 is 68691579012.

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

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 190186 + ... + 279938.

Almost surely, 2^21097519686 is an apocalyptic number.

21097519686 is an abundant number, since it is smaller than the sum of its proper divisors (26209659618).

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

21097519686 is a wasteful number, since it uses less digits than its factorization.

21097519686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91218 (or 91209 counting only the distinct ones).

The product of its (nonzero) digits is 1632960, while the sum is 54.

The spelling of 21097519686 in words is "twenty-one billion, ninety-seven million, five hundred nineteen thousand, six hundred eighty-six".