16805213 has 4 divisors (see below), whose sum is σ = 16813440. Its totient is φ = 16796988.

The previous prime is 16805209. The next prime is 16805219. The reversal of 16805213 is 31250861.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 31250861 = 809 ⋅38629.

It is a cyclic number.

It is not a de Polignac number, because 16805213 - 2² = 16805209 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 (16805219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1556 + ... + 6002.

It is an arithmetic number, because the mean of its divisors is an integer number (4203360).

Almost surely, 2^16805213 is an apocalyptic number.

It is an amenable number.

16805213 is a deficient number, since it is larger than the sum of its proper divisors (8227).

16805213 is an equidigital number, since it uses as much as digits as its factorization.

16805213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8226.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 16805213 is about 4099.4161779453. The cubic root of 16805213 is about 256.1423209690.

The spelling of 16805213 in words is "sixteen million, eight hundred five thousand, two hundred thirteen".