16638905 has 8 divisors (see below), whose sum is σ = 20124672. Its totient is φ = 13205808.

The previous prime is 16638883. The next prime is 16638917. The reversal of 16638905 is 50983661.

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 16638905 - 2¹⁸ = 16376761 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12467 + ... + 13736.

It is an arithmetic number, because the mean of its divisors is an integer number (2515584).

Almost surely, 2^16638905 is an apocalyptic number.

It is an amenable number.

16638905 is a deficient number, since it is larger than the sum of its proper divisors (3485767).

16638905 is a wasteful number, since it uses less digits than its factorization.

16638905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26335.

The product of its (nonzero) digits is 38880, while the sum is 38.

The square root of 16638905 is about 4079.0813916861. The cubic root of 16638905 is about 255.2945717977.

The spelling of 16638905 in words is "sixteen million, six hundred thirty-eight thousand, nine hundred five".