663977 has 2 divisors, whose sum is σ = 663978. Its totient is φ = 663976.

The previous prime is 663973. The next prime is 663979. The reversal of 663977 is 779366.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 512656 + 151321 = 716^2 + 389^2 .

It is a cyclic number.

It is not a de Polignac number, because 663977 - 2² = 663973 is a prime.

Together with 663979, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 663977.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 663977.

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, 331988 + 331989.

It is an arithmetic number, because the mean of its divisors is an integer number (331989).

2⁶⁶³⁹⁷⁷ is an apocalyptic number.

It is an amenable number.

663977 is a deficient number, since it is larger than the sum of its proper divisors (1).

663977 is an equidigital number, since it uses as much as digits as its factorization.

663977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 47628, while the sum is 38.

The square root of 663977 is about 814.8478385564. The cubic root of 663977 is about 87.2404061120.

The spelling of 663977 in words is "six hundred sixty-three thousand, nine hundred seventy-seven".