251605603201 has 2 divisors, whose sum is σ = 251605603202. Its totient is φ = 251605603200.

The previous prime is 251605603199. The next prime is 251605603213. The reversal of 251605603201 is 102306506152.

251605603201 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 129203583601 + 122402019600 = 359449^2 + 349860^2 .

It is a cyclic number.

It is not a de Polignac number, because 251605603201 - 2¹ = 251605603199 is a prime.

It is a super-2 number, since 2×251605603201² (a number of 24 digits) contains 22 as substring.

Together with 251605603199, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (251605673201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125802801600 + 125802801601.

It is an arithmetic number, because the mean of its divisors is an integer number (125802801601).

Almost surely, 2^251605603201 is an apocalyptic number.

It is an amenable number.

251605603201 is a deficient number, since it is larger than the sum of its proper divisors (1).

251605603201 is an equidigital number, since it uses as much as digits as its factorization.

251605603201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10800, while the sum is 31.

The spelling of 251605603201 in words is "two hundred fifty-one billion, six hundred five million, six hundred three thousand, two hundred one".