231020251 has 24 divisors (see below), whose sum is σ = 295840944. Its totient is φ = 178375680.

The previous prime is 231020249. The next prime is 231020287. The reversal of 231020251 is 152020132.

It is not a de Polignac number, because 231020251 - 2¹ = 231020249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (231020051) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 59011 + ... + 62803.

It is an arithmetic number, because the mean of its divisors is an integer number (12326706).

Almost surely, 2^231020251 is an apocalyptic number.

231020251 is a deficient number, since it is larger than the sum of its proper divisors (64820693).

231020251 is a wasteful number, since it uses less digits than its factorization.

231020251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3931 (or 3924 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 231020251 is about 15199.3503479590. The cubic root of 231020251 is about 613.5971735913.

Adding to 231020251 its reverse (152020132), we get a palindrome (383040383).

The spelling of 231020251 in words is "two hundred thirty-one million, twenty thousand, two hundred fifty-one".