811979 has 12 divisors (see below), whose sum is σ = 961704. Its totient is φ = 683424.

The previous prime is 811961. The next prime is 811981. The reversal of 811979 is 979118.

811979 = T₁₅₇ + T₁₅₈ + ... + T₂₀₅.

It is a de Polignac number, because none of the positive numbers 2^k-811979 is a prime.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (811919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3464 + ... + 3690.

It is an arithmetic number, because the mean of its divisors is an integer number (80142).

2⁸¹¹⁹⁷⁹ is an apocalyptic number.

811979 is a deficient number, since it is larger than the sum of its proper divisors (149725).

811979 is a wasteful number, since it uses less digits than its factorization.

811979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314 (or 307 counting only the distinct ones).

The product of its digits is 4536, while the sum is 35.

The square root of 811979 is about 901.0987737202. The cubic root of 811979 is about 93.2928296475.

The spelling of 811979 in words is "eight hundred eleven thousand, nine hundred seventy-nine".