251217125 has 8 divisors (see below), whose sum is σ = 313519128. Its totient is φ = 200973600.

The previous prime is 251217121. The next prime is 251217133. The reversal of 251217125 is 521712152.

It can be written as a sum of positive squares in 4 ways, for example, as 5166529 + 246050596 = 2273^2 + 15686^2 .

It is not a de Polignac number, because 251217125 - 2² = 251217121 is a prime.

It is a super-2 number, since 2×251217125² = 126220087786531250, 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 = 251217094 and 251217103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251217121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1004744 + ... + 1004993.

It is an arithmetic number, because the mean of its divisors is an integer number (39189891).

Almost surely, 2^251217125 is an apocalyptic number.

251217125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

251217125 is a deficient number, since it is larger than the sum of its proper divisors (62302003).

251217125 is an equidigital number, since it uses as much as digits as its factorization.

251217125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2009752 (or 2009742 counting only the distinct ones).

The product of its digits is 1400, while the sum is 26.

The square root of 251217125 is about 15849.8304407334. The cubic root of 251217125 is about 630.9811913023.

Adding to 251217125 its reverse (521712152), we get a palindrome (772929277).

The spelling of 251217125 in words is "two hundred fifty-one million, two hundred seventeen thousand, one hundred twenty-five".