21135208670 has 8 divisors (see below), whose sum is σ = 38043375624. Its totient is φ = 8454083464.

The previous prime is 21135208667. The next prime is 21135208687. The reversal of 21135208670 is 7680253112.

It is a happy number.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21135208670.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1056760424 + ... + 1056760443.

It is an arithmetic number, because the mean of its divisors is an integer number (4755421953).

Almost surely, 2^21135208670 is an apocalyptic number.

21135208670 is a deficient number, since it is larger than the sum of its proper divisors (16908166954).

21135208670 is a wasteful number, since it uses less digits than its factorization.

21135208670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2113520874.

The product of its (nonzero) digits is 20160, while the sum is 35.

The spelling of 21135208670 in words is "twenty-one billion, one hundred thirty-five million, two hundred eight thousand, six hundred seventy".