663666407 has 2 divisors, whose sum is σ = 663666408. Its totient is φ = 663666406.

The previous prime is 663666361. The next prime is 663666431. The reversal of 663666407 is 704666366.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 663666407 - 2²² = 659472103 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (663666457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331833203 + 331833204.

It is an arithmetic number, because the mean of its divisors is an integer number (331833204).

Almost surely, 2^663666407 is an apocalyptic number.

663666407 is a deficient number, since it is larger than the sum of its proper divisors (1).

663666407 is an equidigital number, since it uses as much as digits as its factorization.

663666407 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 653184, while the sum is 44.

The square root of 663666407 is about 25761.7236806857. The cubic root of 663666407 is about 872.2680097930.

The spelling of 663666407 in words is "six hundred sixty-three million, six hundred sixty-six thousand, four hundred seven".