251166 has 16 divisors (see below), whose sum is σ = 515088. Its totient is φ = 81600.

The previous prime is 251159. The next prime is 251171. The reversal of 251166 is 661152.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

251166 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 265 + ... + 756.

It is an arithmetic number, because the mean of its divisors is an integer number (32193).

2²⁵¹¹⁶⁶ is an apocalyptic number.

251166 is an abundant number, since it is smaller than the sum of its proper divisors (263922).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

251166 is a wasteful number, since it uses less digits than its factorization.

251166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1067.

The product of its digits is 360, while the sum is 21.

The square root of 251166 is about 501.1646436053. The cubic root of 251166 is about 63.0938384903.

The spelling of 251166 in words is "two hundred fifty-one thousand, one hundred sixty-six".