16601405 has 4 divisors (see below), whose sum is σ = 19921692. Its totient is φ = 13281120.

The previous prime is 16601381. The next prime is 16601407. The reversal of 16601405 is 50410661.

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

It can be written as a sum of positive squares in 2 ways, for example, as 8637721 + 7963684 = 2939^2 + 2822^2 .

It is not a de Polignac number, because 16601405 - 2⁶ = 16601341 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 (16601407) 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, 1660136 + ... + 1660145.

It is an arithmetic number, because the mean of its divisors is an integer number (4980423).

Almost surely, 2^16601405 is an apocalyptic number.

It is an amenable number.

16601405 is a deficient number, since it is larger than the sum of its proper divisors (3320287).

16601405 is an equidigital number, since it uses as much as digits as its factorization.

16601405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3320286.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 16601405 is about 4074.4821756881. The cubic root of 16601405 is about 255.1026371402.

The spelling of 16601405 in words is "sixteen million, six hundred one thousand, four hundred five".