251381849 has 2 divisors, whose sum is σ = 251381850. Its totient is φ = 251381848.

The previous prime is 251381833. The next prime is 251381863. The reversal of 251381849 is 948183152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 208282624 + 43099225 = 14432^2 + 6565^2 .

It is a cyclic number.

It is not a de Polignac number, because 251381849 - 2⁴ = 251381833 is a prime.

It is not a weakly prime, because it can be changed into another prime (251381869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125690924 + 125690925.

It is an arithmetic number, because the mean of its divisors is an integer number (125690925).

Almost surely, 2^251381849 is an apocalyptic number.

It is an amenable number.

251381849 is a deficient number, since it is larger than the sum of its proper divisors (1).

251381849 is an equidigital number, since it uses as much as digits as its factorization.

251381849 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69120, while the sum is 41.

The square root of 251381849 is about 15855.0259854722. The cubic root of 251381849 is about 631.1190734054.

The spelling of 251381849 in words is "two hundred fifty-one million, three hundred eighty-one thousand, eight hundred forty-nine".