20698587921 has 8 divisors (see below), whose sum is σ = 30107037024. Its totient is φ = 12544598720.

The previous prime is 20698587911. The next prime is 20698587953. The reversal of 20698587921 is 12978589602.

It is a happy number.

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 20698587921 - 2¹⁰ = 20698586897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20698587911) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 313614936 + ... + 313615001.

It is an arithmetic number, because the mean of its divisors is an integer number (3763379628).

Almost surely, 2^20698587921 is an apocalyptic number.

It is an amenable number.

20698587921 is a deficient number, since it is larger than the sum of its proper divisors (9408449103).

20698587921 is a wasteful number, since it uses less digits than its factorization.

20698587921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 627229951.

The product of its (nonzero) digits is 4354560, while the sum is 57.

The spelling of 20698587921 in words is "twenty billion, six hundred ninety-eight million, five hundred eighty-seven thousand, nine hundred twenty-one".