267991 has 4 divisors (see below), whose sum is σ = 275272. Its totient is φ = 260712.

The previous prime is 267961. The next prime is 268003. The reversal of 267991 is 199762.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 199762 = 2 ⋅99881.

It is a cyclic number.

It is not a de Polignac number, because 267991 - 2⁵ = 267959 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 (267901) 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, 3585 + ... + 3658.

It is an arithmetic number, because the mean of its divisors is an integer number (68818).

2²⁶⁷⁹⁹¹ is an apocalyptic number.

267991 is a deficient number, since it is larger than the sum of its proper divisors (7281).

267991 is an equidigital number, since it uses as much as digits as its factorization.

267991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7280.

The product of its digits is 6804, while the sum is 34.

The square root of 267991 is about 517.6784716405. The cubic root of 267991 is about 64.4723355513.

The spelling of 267991 in words is "two hundred sixty-seven thousand, nine hundred ninety-one".