231952181 has 2 divisors, whose sum is σ = 231952182. Its totient is φ = 231952180.

The previous prime is 231952163. The next prime is 231952183. The reversal of 231952181 is 181259132.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 153983281 + 77968900 = 12409^2 + 8830^2 .

It is a cyclic number.

It is not a de Polignac number, because 231952181 - 2²⁶ = 164843317 is a prime.

It is a super-2 number, since 2×231952181² = 107603628541313522, which contains 22 as substring.

Together with 231952183, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231952183) 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 as a sum of consecutive naturals, namely, 115976090 + 115976091.

It is an arithmetic number, because the mean of its divisors is an integer number (115976091).

Almost surely, 2^231952181 is an apocalyptic number.

It is an amenable number.

231952181 is a deficient number, since it is larger than the sum of its proper divisors (1).

231952181 is an equidigital number, since it uses as much as digits as its factorization.

231952181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4320, while the sum is 32.

The square root of 231952181 is about 15229.9763952542. The cubic root of 231952181 is about 614.4211452483.

The spelling of 231952181 in words is "two hundred thirty-one million, nine hundred fifty-two thousand, one hundred eighty-one".