251535133 has 2 divisors, whose sum is σ = 251535134. Its totient is φ = 251535132.

The previous prime is 251535121. The next prime is 251535143. The reversal of 251535133 is 331535152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 219691684 + 31843449 = 14822^2 + 5643^2 .

It is a cyclic number.

It is not a de Polignac number, because 251535133 - 2⁵ = 251535101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251535103) 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, 125767566 + 125767567.

It is an arithmetic number, because the mean of its divisors is an integer number (125767567).

Almost surely, 2^251535133 is an apocalyptic number.

It is an amenable number.

251535133 is a deficient number, since it is larger than the sum of its proper divisors (1).

251535133 is an equidigital number, since it uses as much as digits as its factorization.

251535133 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6750, while the sum is 28.

The square root of 251535133 is about 15859.8591733975. The cubic root of 251535133 is about 631.2473255711.

The spelling of 251535133 in words is "two hundred fifty-one million, five hundred thirty-five thousand, one hundred thirty-three".