16209091 has 4 divisors (see below), whose sum is σ = 16218000. Its totient is φ = 16200184.

The previous prime is 16209077. The next prime is 16209097. The reversal of 16209091 is 19090261.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 16209091 - 2⁹ = 16208579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16209097) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 631 + ... + 5728.

It is an arithmetic number, because the mean of its divisors is an integer number (4054500).

Almost surely, 2^16209091 is an apocalyptic number.

16209091 is a deficient number, since it is larger than the sum of its proper divisors (8909).

16209091 is an equidigital number, since it uses as much as digits as its factorization.

16209091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8908.

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 16209091 is about 4026.0515396602. The cubic root of 16209091 is about 253.0771218900.

The spelling of 16209091 in words is "sixteen million, two hundred nine thousand, ninety-one".