21367519231 has 4 divisors (see below), whose sum is σ = 21393546264. Its totient is φ = 21341492200.

The previous prime is 21367519223. The next prime is 21367519247. The reversal of 21367519231 is 13291576312.

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 21367519231 - 2³ = 21367519223 is a prime.

It is a super-2 number, since 2×21367519231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21367529231) 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, 13012285 + ... + 13013926.

It is an arithmetic number, because the mean of its divisors is an integer number (5348386566).

Almost surely, 2^21367519231 is an apocalyptic number.

21367519231 is a deficient number, since it is larger than the sum of its proper divisors (26027033).

21367519231 is an equidigital number, since it uses as much as digits as its factorization.

21367519231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26027032.

The product of its digits is 68040, while the sum is 40.

The spelling of 21367519231 in words is "twenty-one billion, three hundred sixty-seven million, five hundred nineteen thousand, two hundred thirty-one".