231530155 has 4 divisors (see below), whose sum is σ = 277836192. Its totient is φ = 185224120.

The previous prime is 231530153. The next prime is 231530161. The reversal of 231530155 is 551035132.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 231530155 - 2¹ = 231530153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231530153) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23153011 + ... + 23153020.

It is an arithmetic number, because the mean of its divisors is an integer number (69459048).

Almost surely, 2^231530155 is an apocalyptic number.

231530155 is a deficient number, since it is larger than the sum of its proper divisors (46306037).

231530155 is an equidigital number, since it uses as much as digits as its factorization.

231530155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46306036.

The product of its (nonzero) digits is 2250, while the sum is 25.

The square root of 231530155 is about 15216.1149772207. The cubic root of 231530155 is about 614.0482823035.

Adding to 231530155 its reverse (551035132), we get a palindrome (782565287).

The spelling of 231530155 in words is "two hundred thirty-one million, five hundred thirty thousand, one hundred fifty-five".