23121311 has 4 divisors (see below), whose sum is σ = 23146824. Its totient is φ = 23095800.

The previous prime is 23121283. The next prime is 23121331. The reversal of 23121311 is 11312132.

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 23121311 - 2⁶ = 23121247 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 (23121331) 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, 11345 + ... + 13226.

It is an arithmetic number, because the mean of its divisors is an integer number (5786706).

Almost surely, 2^23121311 is an apocalyptic number.

23121311 is a deficient number, since it is larger than the sum of its proper divisors (25513).

23121311 is an equidigital number, since it uses as much as digits as its factorization.

23121311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25512.

The product of its digits is 36, while the sum is 14.

The square root of 23121311 is about 4808.4624361640. The cubic root of 23121311 is about 284.8858104152.

Adding to 23121311 its reverse (11312132), we get a palindrome (34433443).

It can be divided in two parts, 2312131 and 1, that added together give a palindrome (2312132).

The spelling of 23121311 in words is "twenty-three million, one hundred twenty-one thousand, three hundred eleven".