19804805 has 8 divisors (see below), whose sum is σ = 24408312. Its totient is φ = 15415488.

The previous prime is 19804801. The next prime is 19804819. The reversal of 19804805 is 50840891.

It can be written as a sum of positive squares in 4 ways, for example, as 8305924 + 11498881 = 2882^2 + 3391^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 19804805 - 2² = 19804801 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 (19804801) 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 7 ways as a sum of consecutive naturals, for example, 53342 + ... + 53711.

It is an arithmetic number, because the mean of its divisors is an integer number (3051039).

Almost surely, 2^19804805 is an apocalyptic number.

It is an amenable number.

19804805 is a deficient number, since it is larger than the sum of its proper divisors (4603507).

19804805 is a wasteful number, since it uses less digits than its factorization.

19804805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107095.

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 19804805 is about 4450.2589812279. The cubic root of 19804805 is about 270.5558052288. Note that the first 3 decimals are identical.

The spelling of 19804805 in words is "nineteen million, eight hundred four thousand, eight hundred five".