16605399 has 4 divisors (see below), whose sum is σ = 22140536. Its totient is φ = 11070264.

The previous prime is 16605397. The next prime is 16605401. The reversal of 16605399 is 99350661.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (16605397) and next prime (16605401).

It is not a de Polignac number, because 16605399 - 2¹ = 16605397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16605397) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2767564 + ... + 2767569.

It is an arithmetic number, because the mean of its divisors is an integer number (5535134).

Almost surely, 2^16605399 is an apocalyptic number.

16605399 is a deficient number, since it is larger than the sum of its proper divisors (5535137).

16605399 is an equidigital number, since it uses as much as digits as its factorization.

16605399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5535136.

The product of its (nonzero) digits is 43740, while the sum is 39.

The square root of 16605399 is about 4074.9722698443. The cubic root of 16605399 is about 255.1230932047.

The spelling of 16605399 in words is "sixteen million, six hundred five thousand, three hundred ninety-nine".