16821897 has 16 divisors (see below), whose sum is σ = 23699520. Its totient is φ = 10584000.

The previous prime is 16821887. The next prime is 16821899. The reversal of 16821897 is 79812861.

It is not a de Polignac number, because 16821897 - 2⁴ = 16821881 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16821899) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23647 + ... + 24347.

It is an arithmetic number, because the mean of its divisors is an integer number (1481220).

Almost surely, 2^16821897 is an apocalyptic number.

It is an amenable number.

16821897 is a deficient number, since it is larger than the sum of its proper divisors (6877623).

16821897 is a wasteful number, since it uses less digits than its factorization.

16821897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1144.

The product of its digits is 48384, while the sum is 42.

The square root of 16821897 is about 4101.4505970449. The cubic root of 16821897 is about 256.2270578707.

The spelling of 16821897 in words is "sixteen million, eight hundred twenty-one thousand, eight hundred ninety-seven".