23112131221 has 4 divisors (see below), whose sum is σ = 24328559200. Its totient is φ = 21895703244.

The previous prime is 23112131149. The next prime is 23112131243. The reversal of 23112131221 is 12213121132.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23112131221 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 1216427959 = 23112131221 / (2 + 3 + 1 + 1 + 2 + 1 + 3 + 1 + 2 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23112131291) 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, 608213961 + ... + 608213998.

It is an arithmetic number, because the mean of its divisors is an integer number (6082139800).

Almost surely, 2^23112131221 is an apocalyptic number.

It is an amenable number.

23112131221 is a deficient number, since it is larger than the sum of its proper divisors (1216427979).

23112131221 is a wasteful number, since it uses less digits than its factorization.

23112131221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1216427978.

The product of its digits is 144, while the sum is 19.

Adding to 23112131221 its reverse (12213121132), we get a palindrome (35325252353).

The spelling of 23112131221 in words is "twenty-three billion, one hundred twelve million, one hundred thirty-one thousand, two hundred twenty-one".