231630557 has 2 divisors, whose sum is σ = 231630558. Its totient is φ = 231630556.

The previous prime is 231630541. The next prime is 231630563. The reversal of 231630557 is 755036132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 231374521 + 256036 = 15211^2 + 506^2 .

It is a cyclic number.

It is not a de Polignac number, because 231630557 - 2⁴ = 231630541 is a prime.

It is a super-2 number, since 2×231630557² = 107305429872260498, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231630257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115815278 + 115815279.

It is an arithmetic number, because the mean of its divisors is an integer number (115815279).

Almost surely, 2^231630557 is an apocalyptic number.

It is an amenable number.

231630557 is a deficient number, since it is larger than the sum of its proper divisors (1).

231630557 is an equidigital number, since it uses as much as digits as its factorization.

231630557 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18900, while the sum is 32.

The square root of 231630557 is about 15219.4138191982. The cubic root of 231630557 is about 614.1370292259.

Adding to 231630557 its reverse (755036132), we get a palindrome (986666689).

The spelling of 231630557 in words is "two hundred thirty-one million, six hundred thirty thousand, five hundred fifty-seven".