16821939 has 8 divisors (see below), whose sum is σ = 23035600. Its totient is φ = 10911456.

The previous prime is 16821929. The next prime is 16821953. The reversal of 16821939 is 93912861.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 16821939 - 2⁴ = 16821923 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16821897 and 16821906.

It is not an unprimeable number, because it can be changed into a prime (16821929) 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 7 ways as a sum of consecutive naturals, for example, 75664 + ... + 75885.

It is an arithmetic number, because the mean of its divisors is an integer number (2879450).

Almost surely, 2^16821939 is an apocalyptic number.

16821939 is a deficient number, since it is larger than the sum of its proper divisors (6213661).

16821939 is a wasteful number, since it uses less digits than its factorization.

16821939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151589.

The product of its digits is 23328, while the sum is 39.

The square root of 16821939 is about 4101.4557171814. The cubic root of 16821939 is about 256.2272711151.

The spelling of 16821939 in words is "sixteen million, eight hundred twenty-one thousand, nine hundred thirty-nine".