19810804 has 12 divisors (see below), whose sum is σ = 37335844. Its totient is φ = 9143424.

The previous prime is 19810801. The next prime is 19810811. The reversal of 19810804 is 40801891.

It can be written as a sum of positive squares in 2 ways, for example, as 12531600 + 7279204 = 3540^2 + 2698^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19810801) 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 3 ways as a sum of consecutive naturals, for example, 190437 + ... + 190540.

Almost surely, 2^19810804 is an apocalyptic number.

It is an amenable number.

19810804 is a deficient number, since it is larger than the sum of its proper divisors (17525040).

19810804 is a wasteful number, since it uses less digits than its factorization.

19810804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380994 (or 380992 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 19810804 is about 4450.9329359135. The cubic root of 19810804 is about 270.5831201561.

The spelling of 19810804 in words is "nineteen million, eight hundred ten thousand, eight hundred four".