251161387 has 2 divisors, whose sum is σ = 251161388. Its totient is φ = 251161386.

The previous prime is 251161381. The next prime is 251161429. The reversal of 251161387 is 783161152.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 251161387 - 2²³ = 242772779 is a prime.

It is not a weakly prime, because it can be changed into another prime (251161381) 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, 125580693 + 125580694.

It is an arithmetic number, because the mean of its divisors is an integer number (125580694).

Almost surely, 2^251161387 is an apocalyptic number.

251161387 is a deficient number, since it is larger than the sum of its proper divisors (1).

251161387 is an equidigital number, since it uses as much as digits as its factorization.

251161387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10080, while the sum is 34.

The square root of 251161387 is about 15848.0720278525. The cubic root of 251161387 is about 630.9345222028.

The spelling of 251161387 in words is "two hundred fifty-one million, one hundred sixty-one thousand, three hundred eighty-seven".