663616687 has 2 divisors, whose sum is σ = 663616688. Its totient is φ = 663616686.

The previous prime is 663616661. The next prime is 663616691. The reversal of 663616687 is 786616366.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 663616687 - 2⁷ = 663616559 is a prime.

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 663616687.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (663616637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331808343 + 331808344.

It is an arithmetic number, because the mean of its divisors is an integer number (331808344).

Almost surely, 2^663616687 is an apocalyptic number.

663616687 is a deficient number, since it is larger than the sum of its proper divisors (1).

663616687 is an equidigital number, since it uses as much as digits as its factorization.

663616687 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1306368, while the sum is 49.

The square root of 663616687 is about 25760.7586650704. The cubic root of 663616687 is about 872.2462266361.

The spelling of 663616687 in words is "six hundred sixty-three million, six hundred sixteen thousand, six hundred eighty-seven".