251125505 has 4 divisors (see below), whose sum is σ = 301350612. Its totient is φ = 200900400.

The previous prime is 251125499. The next prime is 251125507. The reversal of 251125505 is 505521152.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 60575089 + 190550416 = 7783^2 + 13804^2 .

It is not a de Polignac number, because 251125505 - 2¹⁶ = 251059969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (251125507) 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, 25112546 + ... + 25112555.

It is an arithmetic number, because the mean of its divisors is an integer number (75337653).

Almost surely, 2^251125505 is an apocalyptic number.

It is an amenable number.

251125505 is a deficient number, since it is larger than the sum of its proper divisors (50225107).

251125505 is an equidigital number, since it uses as much as digits as its factorization.

251125505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50225106.

The product of its (nonzero) digits is 2500, while the sum is 26.

The square root of 251125505 is about 15846.9399254241. The cubic root of 251125505 is about 630.9044747620.

Adding to 251125505 its reverse (505521152), we get a palindrome (756646657).

The spelling of 251125505 in words is "two hundred fifty-one million, one hundred twenty-five thousand, five hundred five".