16821418 has 8 divisors (see below), whose sum is σ = 26329248. Its totient is φ = 8045004.

The previous prime is 16821407. The next prime is 16821433. The reversal of 16821418 is 81412861.

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

It is a self number, because there is not a number n which added to its sum of digits gives 16821418.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 182796 + ... + 182887.

It is an arithmetic number, because the mean of its divisors is an integer number (3291156).

Almost surely, 2^16821418 is an apocalyptic number.

16821418 is a deficient number, since it is larger than the sum of its proper divisors (9507830).

16821418 is a wasteful number, since it uses less digits than its factorization.

16821418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365708.

The product of its digits is 3072, while the sum is 31.

The square root of 16821418 is about 4101.3922026551. The cubic root of 16821418 is about 256.2246258436.

The spelling of 16821418 in words is "sixteen million, eight hundred twenty-one thousand, four hundred eighteen".