268391 has 4 divisors (see below), whose sum is σ = 273000. Its totient is φ = 263784.

The previous prime is 268343. The next prime is 268403. The reversal of 268391 is 193862.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 193862 = 2 ⋅96931.

It is a cyclic number.

It is not a de Polignac number, because 268391 - 2¹⁸ = 6247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (268091) 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, 2216 + ... + 2333.

It is an arithmetic number, because the mean of its divisors is an integer number (68250).

2²⁶⁸³⁹¹ is an apocalyptic number.

268391 is a deficient number, since it is larger than the sum of its proper divisors (4609).

268391 is an equidigital number, since it uses as much as digits as its factorization.

268391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4608.

The product of its digits is 2592, while the sum is 29.

The square root of 268391 is about 518.0646677781. The cubic root of 268391 is about 64.5043964713.

Subtracting from 268391 its reverse (193862), we obtain a square (74529 = 273²).

The spelling of 268391 in words is "two hundred sixty-eight thousand, three hundred ninety-one".