16821423 has 12 divisors (see below), whose sum is σ = 24384360. Its totient is φ = 11174256.

The previous prime is 16821407. The next prime is 16821433. The reversal of 16821423 is 32412861.

It is not a de Polignac number, because 16821423 - 2⁴ = 16821407 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16821433) 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 11 ways as a sum of consecutive naturals, for example, 553 + ... + 5826.

It is an arithmetic number, because the mean of its divisors is an integer number (2032030).

Almost surely, 2^16821423 is an apocalyptic number.

16821423 is a deficient number, since it is larger than the sum of its proper divisors (7562937).

16821423 is a wasteful number, since it uses less digits than its factorization.

16821423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6678 (or 6675 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 16821423 is about 4101.3928122042. The cubic root of 16821423 is about 256.2246512304.

The spelling of 16821423 in words is "sixteen million, eight hundred twenty-one thousand, four hundred twenty-three".