817979 has 2 divisors, whose sum is σ = 817980. Its totient is φ = 817978.

The previous prime is 817951. The next prime is 817987. The reversal of 817979 is 979718.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 817979 - 2⁸ = 817723 is a prime.

It is a Chen prime.

It is a plaindrome in base 15.

It is not a weakly prime, because it can be changed into another prime (817919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 408989 + 408990.

It is an arithmetic number, because the mean of its divisors is an integer number (408990).

2⁸¹⁷⁹⁷⁹ is an apocalyptic number.

817979 is a deficient number, since it is larger than the sum of its proper divisors (1).

817979 is an equidigital number, since it uses as much as digits as its factorization.

817979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31752, while the sum is 41.

The square root of 817979 is about 904.4219148163. The cubic root of 817979 is about 93.5220571943.

The spelling of 817979 in words is "eight hundred seventeen thousand, nine hundred seventy-nine".