20019820 has 24 divisors (see below), whose sum is σ = 42159600. Its totient is φ = 7985472.

The previous prime is 20019817. The next prime is 20019827. The reversal of 20019820 is 2891002.

It is a junction number, because it is equal to n+sod(n) for n = 20019791 and 20019800.

It is not an unprimeable number, because it can be changed into a prime (20019827) 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 7 ways as a sum of consecutive naturals, for example, 7186 + ... + 9574.

It is an arithmetic number, because the mean of its divisors is an integer number (1756650).

Almost surely, 2^20019820 is an apocalyptic number.

20019820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20019820 is an abundant number, since it is smaller than the sum of its proper divisors (22139780).

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

20019820 is a wasteful number, since it uses less digits than its factorization.

20019820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2817 (or 2815 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 20019820 is about 4474.3513496372. The cubic root of 20019820 is about 271.5313983180.

The spelling of 20019820 in words is "twenty million, nineteen thousand, eight hundred twenty".