19840028 has 48 divisors (see below), whose sum is σ = 40360320. Its totient is φ = 8455104.

The previous prime is 19840021. The next prime is 19840033. The reversal of 19840028 is 82004891.

It is a happy number.

It is a super-2 number, since 2×19840028² = 787253422081568, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 19839976 and 19840003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19840021) 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 15 ways as a sum of consecutive naturals, for example, 42251 + ... + 42717.

It is an arithmetic number, because the mean of its divisors is an integer number (840840).

Almost surely, 2^19840028 is an apocalyptic number.

It is an amenable number.

19840028 is an abundant number, since it is smaller than the sum of its proper divisors (20520292).

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

19840028 is a wasteful number, since it uses less digits than its factorization.

19840028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 546 (or 544 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 19840028 is about 4454.2146333557. The cubic root of 19840028 is about 270.7161054372.

The spelling of 19840028 in words is "nineteen million, eight hundred forty thousand, twenty-eight".