16905 has 24 divisors (see below), whose sum is σ = 32832. Its totient is φ = 7392.

The previous prime is 16903. The next prime is 16921. The reversal of 16905 is 50961.

16905 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 16905 - 2¹ = 16903 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is a plaindrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (16901) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 724 + ... + 746.

It is an arithmetic number, because the mean of its divisors is an integer number (1368).

2¹⁶⁹⁰⁵ is an apocalyptic number.

16905 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

16905 is a deficient number, since it is larger than the sum of its proper divisors (15927).

16905 is a wasteful number, since it uses less digits than its factorization.

16905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45 (or 38 counting only the distinct ones).

The product of its (nonzero) digits is 270, while the sum is 21.

The square root of 16905 is about 130.0192293470. The cubic root of 16905 is about 25.6648299879.

The spelling of 16905 in words is "sixteen thousand, nine hundred five".