251505113 has 2 divisors, whose sum is σ = 251505114. Its totient is φ = 251505112.

The previous prime is 251505103. The next prime is 251505119. The reversal of 251505113 is 311505152.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 244703449 + 6801664 = 15643^2 + 2608^2 .

It is a cyclic number.

It is not a de Polignac number, because 251505113 - 2⁴ = 251505097 is a prime.

It is a super-3 number, since 3×251505113³ (a number of 26 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (251505119) 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, 125752556 + 125752557.

It is an arithmetic number, because the mean of its divisors is an integer number (125752557).

Almost surely, 2^251505113 is an apocalyptic number.

It is an amenable number.

251505113 is a deficient number, since it is larger than the sum of its proper divisors (1).

251505113 is an equidigital number, since it uses as much as digits as its factorization.

251505113 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 750, while the sum is 23.

The square root of 251505113 is about 15858.9127307013. The cubic root of 251505113 is about 631.2222120500. Note that the first 4 decimals are identical.

The spelling of 251505113 in words is "two hundred fifty-one million, five hundred five thousand, one hundred thirteen".