56231309 has 2 divisors, whose sum is σ = 56231310. Its totient is φ = 56231308.

The previous prime is 56231299. The next prime is 56231321. The reversal of 56231309 is 90313265.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36844900 + 19386409 = 6070^2 + 4403^2 .

It is a cyclic number.

It is not a de Polignac number, because 56231309 - 2²⁰ = 55182733 is a prime.

It is a super-2 number, since 2×56231309² = 6323920223706962, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56231339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28115654 + 28115655.

It is an arithmetic number, because the mean of its divisors is an integer number (28115655).

Almost surely, 2^56231309 is an apocalyptic number.

It is an amenable number.

56231309 is a deficient number, since it is larger than the sum of its proper divisors (1).

56231309 is an equidigital number, since it uses as much as digits as its factorization.

56231309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4860, while the sum is 29.

The square root of 56231309 is about 7498.7538298040. The cubic root of 56231309 is about 383.1122727113.

The spelling of 56231309 in words is "fifty-six million, two hundred thirty-one thousand, three hundred nine".