251968 has 28 divisors (see below), whose sum is σ = 520192. Its totient is φ = 120960.

The previous prime is 251947. The next prime is 251969. The reversal of 251968 is 869152.

251968 is an admirable number.

It is a super-3 number, since 3×251968³ = 47990737170333696, which contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

Its product of digits (4320) is a multiple of the sum of its prime divisors (160).

It is a nialpdrome in base 8.

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 (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1921 + ... + 2047.

2²⁵¹⁹⁶⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 251968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (260096).

251968 is an abundant number, since it is smaller than the sum of its proper divisors (268224).

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

251968 is a wasteful number, since it uses less digits than its factorization.

251968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170 (or 160 counting only the distinct ones).

The product of its digits is 4320, while the sum is 31.

The square root of 251968 is about 501.9641421456. The cubic root of 251968 is about 63.1609222720.

251968 divided by its sum of digits (31) gives a triangular number (8128 = T₁₂₇).

The spelling of 251968 in words is "two hundred fifty-one thousand, nine hundred sixty-eight".