251531230312 has 16 divisors (see below), whose sum is σ = 479352550500. Its totient is φ = 123703883520.

The previous prime is 251531230261. The next prime is 251531230319. The reversal of 251531230312 is 213032135152.

It can be written as a sum of positive squares in 2 ways, for example, as 177151759236 + 74379471076 = 420894^2 + 272726^2 .

It is not an unprimeable number, because it can be changed into a prime (251531230319) 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, 257715937 + ... + 257716912.

Almost surely, 2^251531230312 is an apocalyptic number.

It is an amenable number.

251531230312 is a deficient number, since it is larger than the sum of its proper divisors (227821320188).

251531230312 is a wasteful number, since it uses less digits than its factorization.

251531230312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 515432916 (or 515432912 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 28.

Adding to 251531230312 its reverse (213032135152), we get a palindrome (464563365464).

The spelling of 251531230312 in words is "two hundred fifty-one billion, five hundred thirty-one million, two hundred thirty thousand, three hundred twelve".