16216891 has 4 divisors (see below), whose sum is σ = 16594072. Its totient is φ = 15839712.

The previous prime is 16216873. The next prime is 16216903. The reversal of 16216891 is 19861261.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 16216891 - 2⁷ = 16216763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16216801) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 188526 + ... + 188611.

It is an arithmetic number, because the mean of its divisors is an integer number (4148518).

Almost surely, 2^16216891 is an apocalyptic number.

16216891 is a deficient number, since it is larger than the sum of its proper divisors (377181).

16216891 is an equidigital number, since it uses as much as digits as its factorization.

16216891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 377180.

The product of its digits is 5184, while the sum is 34.

The square root of 16216891 is about 4027.0201141787. The cubic root of 16216891 is about 253.1177099155.

The spelling of 16216891 in words is "sixteen million, two hundred sixteen thousand, eight hundred ninety-one".