251025631 has 4 divisors (see below), whose sum is σ = 259123264. Its totient is φ = 242928000.

The previous prime is 251025629. The next prime is 251025641. The reversal of 251025631 is 136520152.

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 251025631 - 2¹ = 251025629 is a prime.

It is a super-2 number, since 2×251025631² = 126027734837896322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 251025596 and 251025605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251025601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4048770 + ... + 4048831.

It is an arithmetic number, because the mean of its divisors is an integer number (64780816).

Almost surely, 2^251025631 is an apocalyptic number.

251025631 is a deficient number, since it is larger than the sum of its proper divisors (8097633).

251025631 is an equidigital number, since it uses as much as digits as its factorization.

251025631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8097632.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 251025631 is about 15843.7884042927. The cubic root of 251025631 is about 630.8208256073.

Adding to 251025631 its reverse (136520152), we get a palindrome (387545783).

The spelling of 251025631 in words is "two hundred fifty-one million, twenty-five thousand, six hundred thirty-one".