251023231 has 4 divisors (see below), whose sum is σ = 264235000. Its totient is φ = 237811464.

The previous prime is 251023189. The next prime is 251023261. The reversal of 251023231 is 132320152.

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

It is a cyclic number.

It is not a de Polignac number, because 251023231 - 2⁷ = 251023103 is a prime.

It is a super-2 number, since 2×251023231² = 126025325003358722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 13211749 = 251023231 / (2 + 5 + 1 + 0 + 2 + 3 + 2 + 3 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 251023199 and 251023208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251023261) 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, 6605856 + ... + 6605893.

It is an arithmetic number, because the mean of its divisors is an integer number (66058750).

Almost surely, 2^251023231 is an apocalyptic number.

251023231 is a deficient number, since it is larger than the sum of its proper divisors (13211769).

251023231 is a wasteful number, since it uses less digits than its factorization.

251023231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13211768.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 251023231 is about 15843.7126646503. The cubic root of 251023231 is about 630.8188152219.

Adding to 251023231 its reverse (132320152), we get a palindrome (383343383).

The spelling of 251023231 in words is "two hundred fifty-one million, twenty-three thousand, two hundred thirty-one".