19909444 has 27 divisors (see below), whose sum is σ = 36801597. Its totient is φ = 9423744.

The previous prime is 19909433. The next prime is 19909447. The reversal of 19909444 is 44490991.

The square root of 19909444 is 4462.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 8940100 + 10969344 = 2990^2 + 3312^2 .

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19909397 and 19909406.

It is not an unprimeable number, because it can be changed into a prime (19909447) 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 8 ways as a sum of consecutive naturals, for example, 205204 + ... + 205300.

Almost surely, 2^19909444 is an apocalyptic number.

19909444 is the 4462-nd square number.

It is an amenable number.

19909444 is a deficient number, since it is larger than the sum of its proper divisors (16892153).

19909444 is an equidigital number, since it uses as much as digits as its factorization.

19909444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 40.

The cubic root of 19909444 is about 271.0314637833.

Multiplying 19909444 by its product of nonzero digits (46656), we get a square (928895019264 = 963792²).

The spelling of 19909444 in words is "nineteen million, nine hundred nine thousand, four hundred forty-four".