251955601 has 2 divisors, whose sum is σ = 251955602. Its totient is φ = 251955600.

The previous prime is 251955553. The next prime is 251955611. The reversal of 251955601 is 106559152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 223054225 + 28901376 = 14935^2 + 5376^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-251955601 is a prime.

It is not a weakly prime, because it can be changed into another prime (251955611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125977800 + 125977801.

It is an arithmetic number, because the mean of its divisors is an integer number (125977801).

Almost surely, 2^251955601 is an apocalyptic number.

It is an amenable number.

251955601 is a deficient number, since it is larger than the sum of its proper divisors (1).

251955601 is an equidigital number, since it uses as much as digits as its factorization.

251955601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13500, while the sum is 34.

The square root of 251955601 is about 15873.1093677326. The cubic root of 251955601 is about 631.5988623422.

The spelling of 251955601 in words is "two hundred fifty-one million, nine hundred fifty-five thousand, six hundred one".