20020 has 48 divisors (see below), whose sum is σ = 56448. Its totient is φ = 5760.

The previous prime is 20011. The next prime is 20021. The reversal of 20020 is 2002.

It is a Harshad number since it is a multiple of its sum of digits (4).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a nialpdrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 19991 and 20009.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021) by changing a digit.

20020 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1534 + ... + 1546.

It is an arithmetic number, because the mean of its divisors is an integer number (1176).

2²⁰⁰²⁰ is an apocalyptic number.

20020 is a gapful number since it is divisible by the number (20) 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 20020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28224).

20020 is an abundant number, since it is smaller than the sum of its proper divisors (36428).

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

20020 is a wasteful number, since it uses less digits than its factorization.

20020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40 (or 38 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 4.

The square root of 20020 is about 141.4920492466. The cubic root of 20020 is about 27.1532212103.

Adding to 20020 its reverse (2002), we get a palindrome (22022).

The spelling of 20020 in words is "twenty thousand, twenty", and thus it is an iban number.