16821872 has 20 divisors (see below), whose sum is σ = 32706240. Its totient is φ = 8381568.

The previous prime is 16821869. The next prime is 16821881. The reversal of 16821872 is 27812861.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is a congruent number.

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, 3329 + ... + 6687.

It is an arithmetic number, because the mean of its divisors is an integer number (1635312).

Almost surely, 2^16821872 is an apocalyptic number.

It is an amenable number.

16821872 is a deficient number, since it is larger than the sum of its proper divisors (15884368).

16821872 is a wasteful number, since it uses less digits than its factorization.

16821872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3680 (or 3674 counting only the distinct ones).

The product of its digits is 10752, while the sum is 35.

The square root of 16821872 is about 4101.4475493416. The cubic root of 16821872 is about 256.2269309393.

The spelling of 16821872 in words is "sixteen million, eight hundred twenty-one thousand, eight hundred seventy-two".