251121625 has 8 divisors (see below), whose sum is σ = 313399944. Its totient is φ = 200897200.

The previous prime is 251121601. The next prime is 251121631. The reversal of 251121625 is 526121152.

It can be written as a sum of positive squares in 4 ways, for example, as 21780889 + 229340736 = 4667^2 + 15144^2 .

It is not a de Polignac number, because 251121625 - 2⁵ = 251121593 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 251121625.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1004362 + ... + 1004611.

It is an arithmetic number, because the mean of its divisors is an integer number (39174993).

Almost surely, 2^251121625 is an apocalyptic number.

251121625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

251121625 is a deficient number, since it is larger than the sum of its proper divisors (62278319).

251121625 is an equidigital number, since it uses as much as digits as its factorization.

251121625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2008988 (or 2008978 counting only the distinct ones).

The product of its digits is 1200, while the sum is 25.

The square root of 251121625 is about 15846.8175038397. The cubic root of 251121625 is about 630.9012254943.

Adding to 251121625 its reverse (526121152), we get a palindrome (777242777).

The spelling of 251121625 in words is "two hundred fifty-one million, one hundred twenty-one thousand, six hundred twenty-five".