19909406 has 16 divisors (see below), whose sum is σ = 32780160. Its totient is φ = 8993880.

The previous prime is 19909381. The next prime is 19909433. The reversal of 19909406 is 60490991.

It is a self number, because there is not a number n which added to its sum of digits gives 19909406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 965 + ... + 6383.

It is an arithmetic number, because the mean of its divisors is an integer number (2048760).

Almost surely, 2^19909406 is an apocalyptic number.

19909406 is a deficient number, since it is larger than the sum of its proper divisors (12870754).

19909406 is a wasteful number, since it uses less digits than its factorization.

19909406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5599.

The product of its (nonzero) digits is 17496, while the sum is 38.

The square root of 19909406 is about 4461.9957418178. The cubic root of 19909406 is about 271.0312913492.

Adding to 19909406 its sum of digits (38), we get a square (19909444 = 4462²).

The spelling of 19909406 in words is "nineteen million, nine hundred nine thousand, four hundred six".