19409805 has 12 divisors (see below), whose sum is σ = 33643740. Its totient is φ = 10351872.

The previous prime is 19409777. The next prime is 19409807. The reversal of 19409805 is 50890491.

It can be written as a sum of positive squares in 2 ways, for example, as 14333796 + 5076009 = 3786^2 + 2253^2 .

It is not a de Polignac number, because 19409805 - 2⁹ = 19409293 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19409805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19409807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 215620 + ... + 215709.

It is an arithmetic number, because the mean of its divisors is an integer number (2803645).

Almost surely, 2^19409805 is an apocalyptic number.

19409805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19409805 is a deficient number, since it is larger than the sum of its proper divisors (14233935).

19409805 is a wasteful number, since it uses less digits than its factorization.

19409805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 431340 (or 431337 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 19409805 is about 4405.6560237949. The cubic root of 19409805 is about 268.7449986450.

The spelling of 19409805 in words is "nineteen million, four hundred nine thousand, eight hundred five".