231191613 has 6 divisors (see below), whose sum is σ = 333943454. Its totient is φ = 154127736.

The previous prime is 231191593. The next prime is 231191617. The reversal of 231191613 is 316191132.

231191613 is a `hidden beast` number, since 2 + 31 + 19 + 1 + 613 = 666.

It can be written as a sum of positive squares in only one way, i.e., 227798649 + 3392964 = 15093^2 + 1842^2 .

It is not a de Polignac number, because 231191613 - 2¹⁷ = 231060541 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 (231191617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12843970 + ... + 12843987.

Almost surely, 2^231191613 is an apocalyptic number.

It is an amenable number.

231191613 is a deficient number, since it is larger than the sum of its proper divisors (102751841).

231191613 is a wasteful number, since it uses less digits than its factorization.

231191613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25687963 (or 25687960 counting only the distinct ones).

The product of its digits is 972, while the sum is 27.

The square root of 231191613 is about 15204.9864518190. The cubic root of 231191613 is about 613.7488504119.

It can be divided in two parts, 231 and 191613, that added together give a square (191844 = 438²).

The spelling of 231191613 in words is "two hundred thirty-one million, one hundred ninety-one thousand, six hundred thirteen".