231544993 has 2 divisors, whose sum is σ = 231544994. Its totient is φ = 231544992.

The previous prime is 231544939. The next prime is 231545009. The reversal of 231544993 is 399445132.

Together with previous prime (231544939) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 148060224 + 83484769 = 12168^2 + 9137^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231544993 is a prime.

It is a super-2 number, since 2×231544993² = 107226167566740098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (231544193) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115772496 + 115772497.

It is an arithmetic number, because the mean of its divisors is an integer number (115772497).

Almost surely, 2^231544993 is an apocalyptic number.

It is an amenable number.

231544993 is a deficient number, since it is larger than the sum of its proper divisors (1).

231544993 is an equidigital number, since it uses as much as digits as its factorization.

231544993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 116640, while the sum is 40.

The square root of 231544993 is about 15216.6025445892. The cubic root of 231544993 is about 614.0613994628.

The spelling of 231544993 in words is "two hundred thirty-one million, five hundred forty-four thousand, nine hundred ninety-three".