21112313 has 4 divisors (see below), whose sum is σ = 21349620. Its totient is φ = 20875008.

The previous prime is 21112291. The next prime is 21112339. The reversal of 21112313 is 31321112.

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

It can be written as a sum of positive squares in 2 ways, for example, as 9909904 + 11202409 = 3148^2 + 3347^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112313 - 2¹⁸ = 20850169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21112813) 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, 118520 + ... + 118697.

It is an arithmetic number, because the mean of its divisors is an integer number (5337405).

Almost surely, 2^21112313 is an apocalyptic number.

It is an amenable number.

21112313 is a deficient number, since it is larger than the sum of its proper divisors (237307).

21112313 is an equidigital number, since it uses as much as digits as its factorization.

21112313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237306.

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

The square root of 21112313 is about 4594.8137067785. The cubic root of 21112313 is about 276.3833895102.

Adding to 21112313 its reverse (31321112), we get a palindrome (52433425).

The spelling of 21112313 in words is "twenty-one million, one hundred twelve thousand, three hundred thirteen".