251656201 has 2 divisors, whose sum is σ = 251656202. Its totient is φ = 251656200.

The previous prime is 251656123. The next prime is 251656213. The reversal of 251656201 is 102656152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 218892025 + 32764176 = 14795^2 + 5724^2 .

It is a cyclic number.

It is not a de Polignac number, because 251656201 - 2⁹ = 251655689 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 251656201.

It is not a weakly prime, because it can be changed into another prime (251651201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125828100 + 125828101.

It is an arithmetic number, because the mean of its divisors is an integer number (125828101).

Almost surely, 2^251656201 is an apocalyptic number.

It is an amenable number.

251656201 is a deficient number, since it is larger than the sum of its proper divisors (1).

251656201 is an equidigital number, since it uses as much as digits as its factorization.

251656201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 251656201 is about 15863.6755198787. The cubic root of 251656201 is about 631.3485859030.

The spelling of 251656201 in words is "two hundred fifty-one million, six hundred fifty-six thousand, two hundred one".