16909405 has 4 divisors (see below), whose sum is σ = 20291292. Its totient is φ = 13527520.

The previous prime is 16909391. The next prime is 16909447. The reversal of 16909405 is 50490961.

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 4923961 + 11985444 = 2219^2 + 3462^2 .

It is not a de Polignac number, because 16909405 - 2⁹ = 16908893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1690936 + ... + 1690945.

It is an arithmetic number, because the mean of its divisors is an integer number (5072823).

Almost surely, 2^16909405 is an apocalyptic number.

It is an amenable number.

16909405 is a deficient number, since it is larger than the sum of its proper divisors (3381887).

16909405 is an equidigital number, since it uses as much as digits as its factorization.

16909405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3381886.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 16909405 is about 4112.1046922470. The cubic root of 16909405 is about 256.6705898840.

The spelling of 16909405 in words is "sixteen million, nine hundred nine thousand, four hundred five".