16821873 has 6 divisors (see below), whose sum is σ = 24298274. Its totient is φ = 11214576.

The previous prime is 16821869. The next prime is 16821881. The reversal of 16821873 is 37812861.

It can be written as a sum of positive squares in only one way, i.e., 16136289 + 685584 = 4017^2 + 828^2 .

It is not a de Polignac number, because 16821873 - 2² = 16821869 is a prime.

It is a super-2 number, since 2×16821873² = 565950822456258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16821173) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 934540 + ... + 934557.

Almost surely, 2^16821873 is an apocalyptic number.

It is an amenable number.

16821873 is a deficient number, since it is larger than the sum of its proper divisors (7476401).

16821873 is a wasteful number, since it uses less digits than its factorization.

16821873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1869103 (or 1869100 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 16821873 is about 4101.4476712498. The cubic root of 16821873 is about 256.2269360166.

The spelling of 16821873 in words is "sixteen million, eight hundred twenty-one thousand, eight hundred seventy-three".