21513275767 has 4 divisors (see below), whose sum is σ = 21516266376. Its totient is φ = 21510285160.

The previous prime is 21513275761. The next prime is 21513275843. The reversal of 21513275767 is 76757231512.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21513275767 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21513275761) 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, 1484488 + ... + 1498909.

It is an arithmetic number, because the mean of its divisors is an integer number (5379066594).

Almost surely, 2^21513275767 is an apocalyptic number.

21513275767 is a deficient number, since it is larger than the sum of its proper divisors (2990609).

21513275767 is an equidigital number, since it uses as much as digits as its factorization.

21513275767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2990608.

The product of its digits is 617400, while the sum is 46.

The spelling of 21513275767 in words is "twenty-one billion, five hundred thirteen million, two hundred seventy-five thousand, seven hundred sixty-seven".