16660405 has 8 divisors (see below), whose sum is σ = 20019384. Its totient is φ = 13310400.

The previous prime is 16660403. The next prime is 16660417. The reversal of 16660405 is 50406661.

It can be written as a sum of positive squares in 4 ways, for example, as 1868689 + 14791716 = 1367^2 + 3846^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 16660405 - 2¹ = 16660403 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 (16660403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2935 + ... + 6475.

It is an arithmetic number, because the mean of its divisors is an integer number (2502423).

Almost surely, 2^16660405 is an apocalyptic number.

It is an amenable number.

16660405 is a deficient number, since it is larger than the sum of its proper divisors (3358979).

16660405 is an equidigital number, since it uses as much as digits as its factorization.

16660405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4487.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 16660405 is about 4081.7159381809. The cubic root of 16660405 is about 255.4044842960.

The spelling of 16660405 in words is "sixteen million, six hundred sixty thousand, four hundred five".