251381887 has 2 divisors, whose sum is σ = 251381888. Its totient is φ = 251381886.

The previous prime is 251381869. The next prime is 251381909. The reversal of 251381887 is 788183152.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 251381887 - 2¹¹ = 251379839 is a prime.

It is a super-2 number, since 2×251381887² = 126385706223361538, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251381807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125690943 + 125690944.

It is an arithmetic number, because the mean of its divisors is an integer number (125690944).

Almost surely, 2^251381887 is an apocalyptic number.

251381887 is a deficient number, since it is larger than the sum of its proper divisors (1).

251381887 is an equidigital number, since it uses as much as digits as its factorization.

251381887 is an evil number, because the sum of its binary digits is even.

The product of its digits is 107520, while the sum is 43.

The square root of 251381887 is about 15855.0271838304. The cubic root of 251381887 is about 631.1191052063.

The spelling of 251381887 in words is "two hundred fifty-one million, three hundred eighty-one thousand, eight hundred eighty-seven".