811959 has 4 divisors (see below), whose sum is σ = 1082616. Its totient is φ = 541304.

The previous prime is 811957. The next prime is 811961. The reversal of 811959 is 959118.

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

It is an interprime number because it is at equal distance from previous prime (811957) and next prime (811961).

It is a cyclic number.

It is not a de Polignac number, because 811959 - 2¹ = 811957 is a prime.

It is a D-number.

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 811959.

It is not an unprimeable number, because it can be changed into a prime (811957) 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, 135324 + ... + 135329.

It is an arithmetic number, because the mean of its divisors is an integer number (270654).

2⁸¹¹⁹⁵⁹ is an apocalyptic number.

811959 is a deficient number, since it is larger than the sum of its proper divisors (270657).

811959 is a wasteful number, since it uses less digits than its factorization.

811959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270656.

The product of its digits is 3240, while the sum is 33.

The square root of 811959 is about 901.0876760893. The cubic root of 811959 is about 93.2920636704.

It can be divided in two parts, 811 and 959, that added together give a triangular number (1770 = T₅₉).

The spelling of 811959 in words is "eight hundred eleven thousand, nine hundred fifty-nine".