19804238 has 4 divisors (see below), whose sum is σ = 29706360. Its totient is φ = 9902118.

The previous prime is 19804237. The next prime is 19804247. The reversal of 19804238 is 83240891.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83240891 = 17 ⋅4896523.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 19804198 and 19804207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19804231) 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 as a sum of consecutive naturals, namely, 4951058 + ... + 4951061.

It is an arithmetic number, because the mean of its divisors is an integer number (7426590).

Almost surely, 2^19804238 is an apocalyptic number.

19804238 is a deficient number, since it is larger than the sum of its proper divisors (9902122).

19804238 is an equidigital number, since it uses as much as digits as its factorization.

19804238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9902121.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 19804238 is about 4450.1952766143. The cubic root of 19804238 is about 270.5532232526.

The spelling of 19804238 in words is "nineteen million, eight hundred four thousand, two hundred thirty-eight".