251540125 has 16 divisors (see below), whose sum is σ = 321585264. Its totient is φ = 196320000.

The previous prime is 251540089. The next prime is 251540129. The reversal of 251540125 is 521045152.

It can be written as a sum of positive squares in 8 ways, for example, as 150356644 + 101183481 = 12262^2 + 10059^2 .

It is not a de Polignac number, because 251540125 - 2¹⁹ = 251015837 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 251540125.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251540129) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19416 + ... + 29665.

It is an arithmetic number, because the mean of its divisors is an integer number (20099079).

Almost surely, 2^251540125 is an apocalyptic number.

251540125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

251540125 is a deficient number, since it is larger than the sum of its proper divisors (70045139).

251540125 is an equidigital number, since it uses as much as digits as its factorization.

251540125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49137 (or 49127 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 25.

The square root of 251540125 is about 15860.0165510632. The cubic root of 251540125 is about 631.2515014832.

Adding to 251540125 its reverse (521045152), we get a palindrome (772585277).

The spelling of 251540125 in words is "two hundred fifty-one million, five hundred forty thousand, one hundred twenty-five".