251387 has 2 divisors, whose sum is σ = 251388. Its totient is φ = 251386.

The previous prime is 251359. The next prime is 251393. The reversal of 251387 is 783152.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 251387 - 2⁶ = 251323 is a prime.

It is not a weakly prime, because it can be changed into another prime (251347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125693 + 125694.

It is an arithmetic number, because the mean of its divisors is an integer number (125694).

2²⁵¹³⁸⁷ is an apocalyptic number.

251387 is a deficient number, since it is larger than the sum of its proper divisors (1).

251387 is an equidigital number, since it uses as much as digits as its factorization.

251387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1680, while the sum is 26.

The square root of 251387 is about 501.3850815491. The cubic root of 251387 is about 63.1123384075.

The spelling of 251387 in words is "two hundred fifty-one thousand, three hundred eighty-seven".