15997663 has 8 divisors (see below), whose sum is σ = 18478800. Its totient is φ = 13687680.

The previous prime is 15997637. The next prime is 15997691. The reversal of 15997663 is 36679951.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 15997663 - 2⁹ = 15997151 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15997613) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42588 + ... + 42961.

It is an arithmetic number, because the mean of its divisors is an integer number (2309850).

Almost surely, 2^15997663 is an apocalyptic number.

15997663 is a deficient number, since it is larger than the sum of its proper divisors (2481137).

15997663 is a wasteful number, since it uses less digits than its factorization.

15997663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85577.

The product of its digits is 306180, while the sum is 46.

The square root of 15997663 is about 3999.7078643321. The cubic root of 15997663 is about 251.9719409004.

The spelling of 15997663 in words is "fifteen million, nine hundred ninety-seven thousand, six hundred sixty-three".