663979 has 2 divisors, whose sum is σ = 663980. Its totient is φ = 663978.

The previous prime is 663977. The next prime is 663983. The reversal of 663979 is 979366.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 663979 - 2¹ = 663977 is a prime.

It is a super-2 number, since 2×663979² = 881736224882, which contains 22 as substring.

Together with 663977, it forms a pair of twin primes.

It is a Chen prime.

663979 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (663973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331989 + 331990.

It is an arithmetic number, because the mean of its divisors is an integer number (331990).

2⁶⁶³⁹⁷⁹ is an apocalyptic number.

663979 is a deficient number, since it is larger than the sum of its proper divisors (1).

663979 is an equidigital number, since it uses as much as digits as its factorization.

663979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 61236, while the sum is 40.

The square root of 663979 is about 814.8490657784. The cubic root of 663979 is about 87.2404937057.

The spelling of 663979 in words is "six hundred sixty-three thousand, nine hundred seventy-nine".