251575481 has 2 divisors, whose sum is σ = 251575482. Its totient is φ = 251575480.

The previous prime is 251575477. The next prime is 251575483. The reversal of 251575481 is 184575152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 251507881 + 67600 = 15859^2 + 260^2 .

It is a cyclic number.

It is not a de Polignac number, because 251575481 - 2² = 251575477 is a prime.

It is a super-2 number, since 2×251575481² = 126580445280762722, which contains 22 as substring.

Together with 251575483, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (251575483) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125787740 + 125787741.

It is an arithmetic number, because the mean of its divisors is an integer number (125787741).

Almost surely, 2^251575481 is an apocalyptic number.

It is an amenable number.

251575481 is a deficient number, since it is larger than the sum of its proper divisors (1).

251575481 is an equidigital number, since it uses as much as digits as its factorization.

251575481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56000, while the sum is 38.

The square root of 251575481 is about 15861.1311387303. The cubic root of 251575481 is about 631.2810759331.

The spelling of 251575481 in words is "two hundred fifty-one million, five hundred seventy-five thousand, four hundred eighty-one".