19804890 has 32 divisors (see below), whose sum is σ = 54322560. Its totient is φ = 4526784.

The previous prime is 19804871. The next prime is 19804901. The reversal of 19804890 is 9840891.

It is a Curzon number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 46945 + ... + 47364.

It is an arithmetic number, because the mean of its divisors is an integer number (1697580).

Almost surely, 2^19804890 is an apocalyptic number.

19804890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19804890 is an abundant number, since it is smaller than the sum of its proper divisors (34517670).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19804890 is a wasteful number, since it uses less digits than its factorization.

19804890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94326.

The product of its (nonzero) digits is 20736, while the sum is 39.

The square root of 19804890 is about 4450.2685312237. The cubic root of 19804890 is about 270.5561922933.

It can be divided in two parts, 1980 and 4890, that multiplied together give a triangular number (9682200 = T₄₄₀₀).

The spelling of 19804890 in words is "nineteen million, eight hundred four thousand, eight hundred ninety".