251566241 has 2 divisors, whose sum is σ = 251566242. Its totient is φ = 251566240.

The previous prime is 251566229. The next prime is 251566247. The reversal of 251566241 is 142665152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 246615616 + 4950625 = 15704^2 + 2225^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-251566241 is a prime.

It is a super-2 number, since 2×251566241² = 126571147221740162, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 251566198 and 251566207.

It is not a weakly prime, because it can be changed into another prime (251566247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125783120 + 125783121.

It is an arithmetic number, because the mean of its divisors is an integer number (125783121).

Almost surely, 2^251566241 is an apocalyptic number.

It is an amenable number.

251566241 is a deficient number, since it is larger than the sum of its proper divisors (1).

251566241 is an equidigital number, since it uses as much as digits as its factorization.

251566241 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14400, while the sum is 32.

The square root of 251566241 is about 15860.8398579646. The cubic root of 251566241 is about 631.2733471612.

The spelling of 251566241 in words is "two hundred fifty-one million, five hundred sixty-six thousand, two hundred forty-one".