251287 has 2 divisors, whose sum is σ = 251288. Its totient is φ = 251286.

The previous prime is 251263. The next prime is 251291. The reversal of 251287 is 782152.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 251287 - 2⁷ = 251159 is a prime.

It is a d-powerful number, because it can be written as 2¹¹ + 5 + 2¹⁷ + 1 + 8³ + 7⁶ .

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125643 + 125644.

It is an arithmetic number, because the mean of its divisors is an integer number (125644).

2²⁵¹²⁸⁷ is an apocalyptic number.

251287 is a deficient number, since it is larger than the sum of its proper divisors (1).

251287 is an equidigital number, since it uses as much as digits as its factorization.

251287 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1120, while the sum is 25.

The square root of 251287 is about 501.2853478808. The cubic root of 251287 is about 63.1039687478.

The spelling of 251287 in words is "two hundred fifty-one thousand, two hundred eighty-seven".