16866399 has 16 divisors (see below), whose sum is σ = 24716160. Its totient is φ = 10145760.

The previous prime is 16866391. The next prime is 16866419. The reversal of 16866399 is 99366861.

It is not a de Polignac number, because 16866399 - 2³ = 16866391 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16866391) 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, 2749 + ... + 6425.

It is an arithmetic number, because the mean of its divisors is an integer number (1544760).

Almost surely, 2^16866399 is an apocalyptic number.

16866399 is a deficient number, since it is larger than the sum of its proper divisors (7849761).

16866399 is a wasteful number, since it uses less digits than its factorization.

16866399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3830.

The product of its digits is 419904, while the sum is 48.

The square root of 16866399 is about 4106.8721674773. The cubic root of 16866399 is about 256.4528068087.

The spelling of 16866399 in words is "sixteen million, eight hundred sixty-six thousand, three hundred ninety-nine".