231509797 has 2 divisors, whose sum is σ = 231509798. Its totient is φ = 231509796.

The previous prime is 231509779. The next prime is 231509899. The reversal of 231509797 is 797905132.

Together with previous prime (231509779) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 177795556 + 53714241 = 13334^2 + 7329^2 .

It is a cyclic number.

It is not a de Polignac number, because 231509797 - 2⁷ = 231509669 is a prime.

It is a super-2 number, since 2×231509797² = 107193572213962418, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231509297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115754898 + 115754899.

It is an arithmetic number, because the mean of its divisors is an integer number (115754899).

Almost surely, 2^231509797 is an apocalyptic number.

It is an amenable number.

231509797 is a deficient number, since it is larger than the sum of its proper divisors (1).

231509797 is an equidigital number, since it uses as much as digits as its factorization.

231509797 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 119070, while the sum is 43.

The square root of 231509797 is about 15215.4460006928. The cubic root of 231509797 is about 614.0302844156.

The spelling of 231509797 in words is "two hundred thirty-one million, five hundred nine thousand, seven hundred ninety-seven".