231666613 has 2 divisors, whose sum is σ = 231666614. Its totient is φ = 231666612.

The previous prime is 231666581. The next prime is 231666623. The reversal of 231666613 is 316666132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 171557604 + 60109009 = 13098^2 + 7753^2 .

It is a cyclic number.

It is not a de Polignac number, because 231666613 - 2⁵ = 231666581 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231666623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115833306 + 115833307.

It is an arithmetic number, because the mean of its divisors is an integer number (115833307).

Almost surely, 2^231666613 is an apocalyptic number.

It is an amenable number.

231666613 is a deficient number, since it is larger than the sum of its proper divisors (1).

231666613 is an equidigital number, since it uses as much as digits as its factorization.

231666613 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23328, while the sum is 34.

The square root of 231666613 is about 15220.5983128128. The cubic root of 231666613 is about 614.1688934384.

The spelling of 231666613 in words is "two hundred thirty-one million, six hundred sixty-six thousand, six hundred thirteen".