23218521721231 has 4 divisors (see below), whose sum is σ = 23498262946872. Its totient is φ = 22938780495592.

The previous prime is 23218521721229. The next prime is 23218521721253. The reversal of 23218521721231 is 13212712581232.

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 23218521721231 - 2¹ = 23218521721229 is a prime.

It is a super-2 number, since 2×23218521721231² (a number of 28 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 (23218521761231) 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, 139870612696 + ... + 139870612861.

It is an arithmetic number, because the mean of its divisors is an integer number (5874565736718).

Almost surely, 2^{23218521721231} is an apocalyptic number.

23218521721231 is a deficient number, since it is larger than the sum of its proper divisors (279741225641).

23218521721231 is an equidigital number, since it uses as much as digits as its factorization.

23218521721231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 279741225640.

The product of its digits is 80640, while the sum is 40.

The spelling of 23218521721231 in words is "twenty-three trillion, two hundred eighteen billion, five hundred twenty-one million, seven hundred twenty-one thousand, two hundred thirty-one".