16390805 has 8 divisors (see below), whose sum is σ = 20826072. Its totient is φ = 12341248.

The previous prime is 16390799. The next prime is 16390807. The reversal of 16390805 is 50809361.

It can be written as a sum of positive squares in 4 ways, for example, as 117649 + 16273156 = 343^2 + 4034^2 .

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 16390805 - 2¹⁶ = 16325269 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16390807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 96332 + ... + 96501.

It is an arithmetic number, because the mean of its divisors is an integer number (2603259).

Almost surely, 2^16390805 is an apocalyptic number.

It is an amenable number.

16390805 is a deficient number, since it is larger than the sum of its proper divisors (4435267).

16390805 is a wasteful number, since it uses less digits than its factorization.

16390805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192855.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 16390805 is about 4048.5559153851. Note that the first 3 decimals coincide. The cubic root of 16390805 is about 254.0193270680.

The spelling of 16390805 in words is "sixteen million, three hundred ninety thousand, eight hundred five".