275991 has 4 divisors (see below), whose sum is σ = 367992. Its totient is φ = 183992.

The previous prime is 275987. The next prime is 275999. The reversal of 275991 is 199572.

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 275991 - 2² = 275987 is a prime.

It is a D-number.

It is a nialpdrome in base 13.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 275991.

It is not an unprimeable number, because it can be changed into a prime (275999) 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, 45996 + ... + 46001.

It is an arithmetic number, because the mean of its divisors is an integer number (91998).

2²⁷⁵⁹⁹¹ is an apocalyptic number.

275991 is a deficient number, since it is larger than the sum of its proper divisors (92001).

275991 is an equidigital number, since it uses as much as digits as its factorization.

275991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92000.

The product of its digits is 5670, while the sum is 33.

The square root of 275991 is about 525.3484557891. The cubic root of 275991 is about 65.1075930087.

It can be divided in two parts, 2759 and 91, that added together give a triangular number (2850 = T₇₅).

The spelling of 275991 in words is "two hundred seventy-five thousand, nine hundred ninety-one".