16663987 has 2 divisors, whose sum is σ = 16663988. Its totient is φ = 16663986.

The previous prime is 16663963. The next prime is 16664003. The reversal of 16663987 is 78936661.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16663987 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (16661987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8331993 + 8331994.

It is an arithmetic number, because the mean of its divisors is an integer number (8331994).

Almost surely, 2^16663987 is an apocalyptic number.

16663987 is a deficient number, since it is larger than the sum of its proper divisors (1).

16663987 is an equidigital number, since it uses as much as digits as its factorization.

16663987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 326592, while the sum is 46.

The square root of 16663987 is about 4082.1547006452. The cubic root of 16663987 is about 255.4227870385.

The spelling of 16663987 in words is "sixteen million, six hundred sixty-three thousand, nine hundred eighty-seven".