251125531 has 4 divisors (see below), whose sum is σ = 253714552. Its totient is φ = 248536512.

The previous prime is 251125519. The next prime is 251125543. The reversal of 251125531 is 135521152.

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

It is an interprime number because it is at equal distance from previous prime (251125519) and next prime (251125543).

It is a cyclic number.

It is not a de Polignac number, because 251125531 - 2⁵ = 251125499 is a prime.

It is a super-2 number, since 2×251125531² = 126128064640063922, 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 = 251125496 and 251125505.

It is not an unprimeable number, because it can be changed into a prime (251125561) 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, 1294365 + ... + 1294558.

It is an arithmetic number, because the mean of its divisors is an integer number (63428638).

Almost surely, 2^251125531 is an apocalyptic number.

251125531 is a deficient number, since it is larger than the sum of its proper divisors (2589021).

251125531 is an equidigital number, since it uses as much as digits as its factorization.

251125531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2589020.

The product of its digits is 1500, while the sum is 25.

The square root of 251125531 is about 15846.9407457717. The cubic root of 251125531 is about 630.9044965353.

Adding to 251125531 its reverse (135521152), we get a palindrome (386646683).

The spelling of 251125531 in words is "two hundred fifty-one million, one hundred twenty-five thousand, five hundred thirty-one".