231655993 has 2 divisors, whose sum is σ = 231655994. Its totient is φ = 231655992.

The previous prime is 231655981. The next prime is 231656003. The reversal of 231655993 is 399556132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 150601984 + 81054009 = 12272^2 + 9003^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231655993 is a prime.

It is not a weakly prime, because it can be changed into another prime (231655093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115827996 + 115827997.

It is an arithmetic number, because the mean of its divisors is an integer number (115827997).

Almost surely, 2^231655993 is an apocalyptic number.

It is an amenable number.

231655993 is a deficient number, since it is larger than the sum of its proper divisors (1).

231655993 is an equidigital number, since it uses as much as digits as its factorization.

231655993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 218700, while the sum is 43.

The square root of 231655993 is about 15220.2494394803. The cubic root of 231655993 is about 614.1595084387.

The spelling of 231655993 in words is "two hundred thirty-one million, six hundred fifty-five thousand, nine hundred ninety-three".