251139 has 8 divisors (see below), whose sum is σ = 382720. Its totient is φ = 143496.

The previous prime is 251117. The next prime is 251143. The reversal of 251139 is 931152.

251139 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 251139 - 2¹⁵ = 218371 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 11959 = 251139 / (2 + 5 + 1 + 1 + 3 + 9).

It is a Duffinian number.

251139 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (251149) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5959 + ... + 6000.

It is an arithmetic number, because the mean of its divisors is an integer number (47840).

2²⁵¹¹³⁹ is an apocalyptic number.

251139 is a deficient number, since it is larger than the sum of its proper divisors (131581).

251139 is a wasteful number, since it uses less digits than its factorization.

251139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11969.

The product of its digits is 270, while the sum is 21.

The square root of 251139 is about 501.1377056259. The cubic root of 251139 is about 63.0915775756.

The spelling of 251139 in words is "two hundred fifty-one thousand, one hundred thirty-nine".