291139 has 4 divisors (see below), whose sum is σ = 293920. Its totient is φ = 288360.

The previous prime is 291113. The next prime is 291143. The reversal of 291139 is 931192.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 291139 - 2⁵ = 291107 is a prime.

It is a Duffinian number.

291139 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (291169) 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, 1227 + ... + 1444.

It is an arithmetic number, because the mean of its divisors is an integer number (73480).

2²⁹¹¹³⁹ is an apocalyptic number.

291139 is a deficient number, since it is larger than the sum of its proper divisors (2781).

291139 is a wasteful number, since it uses less digits than its factorization.

291139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2780.

The product of its digits is 486, while the sum is 25.

The square root of 291139 is about 539.5729793086. The cubic root of 291139 is about 66.2776033069.

The spelling of 291139 in words is "two hundred ninety-one thousand, one hundred thirty-nine".