251455 has 4 divisors (see below), whose sum is σ = 301752. Its totient is φ = 201160.

The previous prime is 251443. The next prime is 251467. The reversal of 251455 is 554152.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (251443) and next prime (251467).

It is not a de Polignac number, because 251455 - 2¹³ = 243263 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25141 + ... + 25150.

It is an arithmetic number, because the mean of its divisors is an integer number (75438).

2²⁵¹⁴⁵⁵ is an apocalyptic number.

251455 is a deficient number, since it is larger than the sum of its proper divisors (50297).

251455 is an equidigital number, since it uses as much as digits as its factorization.

251455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50296.

The product of its digits is 1000, while the sum is 22.

The square root of 251455 is about 501.4528891132. The cubic root of 251455 is about 63.1180285083.

The spelling of 251455 in words is "two hundred fifty-one thousand, four hundred fifty-five".