21135699683 has 4 divisors (see below), whose sum is σ = 24155085360. Its totient is φ = 18116314008.

The previous prime is 21135699659. The next prime is 21135699691. The reversal of 21135699683 is 38699653112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21135699683 - 2³⁴ = 3955830499 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21135690683) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1509692828 + ... + 1509692841.

It is an arithmetic number, because the mean of its divisors is an integer number (6038771340).

Almost surely, 2^21135699683 is an apocalyptic number.

21135699683 is a deficient number, since it is larger than the sum of its proper divisors (3019385677).

21135699683 is an equidigital number, since it uses as much as digits as its factorization.

21135699683 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3019385676.

The product of its digits is 2099520, while the sum is 53.

The spelling of 21135699683 in words is "twenty-one billion, one hundred thirty-five million, six hundred ninety-nine thousand, six hundred eighty-three".