251461 has 4 divisors (see below), whose sum is σ = 287392. Its totient is φ = 215532.

The previous prime is 251443. The next prime is 251467. The reversal of 251461 is 164152.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 251461 - 2⁵ = 251429 is a prime.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251467) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17955 + ... + 17968.

It is an arithmetic number, because the mean of its divisors is an integer number (71848).

2²⁵¹⁴⁶¹ is an apocalyptic number.

It is an amenable number.

251461 is a deficient number, since it is larger than the sum of its proper divisors (35931).

251461 is an equidigital number, since it uses as much as digits as its factorization.

251461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35930.

The product of its digits is 240, while the sum is 19.

The square root of 251461 is about 501.4588716934. The cubic root of 251461 is about 63.1185305267.

The spelling of 251461 in words is "two hundred fifty-one thousand, four hundred sixty-one".