16648409 has 6 divisors (see below), whose sum is σ = 17111934. Its totient is φ = 16197120.

The previous prime is 16648393. The next prime is 16648421. The reversal of 16648409 is 90484661.

It can be written as a sum of positive squares in 3 ways, for example, as 7038409 + 9610000 = 2653^2 + 3100^2 .

It is not a de Polignac number, because 16648409 - 2⁴ = 16648393 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 (16648469) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4712 + ... + 7449.

It is an arithmetic number, because the mean of its divisors is an integer number (2851989).

Almost surely, 2^16648409 is an apocalyptic number.

It is an amenable number.

16648409 is a deficient number, since it is larger than the sum of its proper divisors (463525).

16648409 is an equidigital number, since it uses as much as digits as its factorization.

16648409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12235 (or 12198 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 16648409 is about 4080.2461935525. The cubic root of 16648409 is about 255.3431699035.

The spelling of 16648409 in words is "sixteen million, six hundred forty-eight thousand, four hundred nine".