19820020 has 48 divisors (see below), whose sum is σ = 47392128. Its totient is φ = 6892160.

The previous prime is 19819999. The next prime is 19820023. The reversal of 19820020 is 2002891.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 19819973 and 19820000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19820023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3102 + ... + 7018.

It is an arithmetic number, because the mean of its divisors is an integer number (987336).

Almost surely, 2^19820020 is an apocalyptic number.

19820020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19820020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23696064).

19820020 is an abundant number, since it is smaller than the sum of its proper divisors (27572108).

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

19820020 is a wasteful number, since it uses less digits than its factorization.

19820020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3960 (or 3958 counting only the distinct ones).

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

The square root of 19820020 is about 4451.9681041086. The cubic root of 19820020 is about 270.6250721375.

The spelling of 19820020 in words is "nineteen million, eight hundred twenty thousand, twenty".