19804990 has 16 divisors (see below), whose sum is σ = 36613152. Its totient is φ = 7707744.

The previous prime is 19804979. The next prime is 19804991. The reversal of 19804990 is 9940891.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19804991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26394 + ... + 27133.

It is an arithmetic number, because the mean of its divisors is an integer number (2288322).

Almost surely, 2^19804990 is an apocalyptic number.

19804990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19804990 is a deficient number, since it is larger than the sum of its proper divisors (16808162).

19804990 is a wasteful number, since it uses less digits than its factorization.

19804990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53571.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 19804990 is about 4450.2797664866. The cubic root of 19804990 is about 270.5566476619.

The spelling of 19804990 in words is "nineteen million, eight hundred four thousand, nine hundred ninety".