251966 has 16 divisors (see below), whose sum is σ = 444528. Its totient is φ = 105600.

The previous prime is 251947. The next prime is 251969. The reversal of 251966 is 669152.

251966 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251969) by changing a digit.

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, 155 + ... + 726.

It is an arithmetic number, because the mean of its divisors is an integer number (27783).

2²⁵¹⁹⁶⁶ is an apocalyptic number.

251966 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

251966 is a deficient number, since it is larger than the sum of its proper divisors (192562).

251966 is a wasteful number, since it uses less digits than its factorization.

251966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 907.

The product of its digits is 3240, while the sum is 29.

The square root of 251966 is about 501.9621499675. The cubic root of 251966 is about 63.1607551580.

It can be divided in two parts, 25 and 1966, that added together give a palindrome (1991).

The spelling of 251966 in words is "two hundred fifty-one thousand, nine hundred sixty-six".