19817842 has 32 divisors (see below), whose sum is σ = 33675264. Its totient is φ = 8668800.

The previous prime is 19817807. The next prime is 19817851. The reversal of 19817842 is 24871891.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 19817795 and 19817804.

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, 114468 + ... + 114640.

It is an arithmetic number, because the mean of its divisors is an integer number (1052352).

Almost surely, 2^19817842 is an apocalyptic number.

19817842 is a deficient number, since it is larger than the sum of its proper divisors (13857422).

19817842 is a wasteful number, since it uses less digits than its factorization.

19817842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354.

The product of its digits is 32256, while the sum is 40.

The square root of 19817842 is about 4451.7234864713. The cubic root of 19817842 is about 270.6151588781.

The spelling of 19817842 in words is "nineteen million, eight hundred seventeen thousand, eight hundred forty-two".