20120 has 16 divisors (see below), whose sum is σ = 45360.
Its totient is φ = 8032.
The previous prime is 20117. The next prime is 20123. The reversal of 20120 is 2102.
It is an interprime number because it is at equal distance from previous prime (20117) and next prime (20123).
It is a Harshad number since it is a multiple of its sum of digits (5).
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (20123) by changing a digit.
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 3 ways as a sum of consecutive naturals, for example, 212 + ... + 291.
It is an arithmetic number, because the mean of its divisors is an integer number (2835).
220120 is an apocalyptic number.
20120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.
It is an amenable number.
20120 is an abundant number, since it is smaller than the sum of its proper divisors (25240).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22680).
20120 is a wasteful number, since it uses less digits than its factorization.
20120 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 514 (or 510 counting only the distinct ones).
The product of its (nonzero) digits is 4, while the sum is 5.
The square root of 20120 is about 141.8449858120.
The cubic root of 20120 is about 27.1983563021.
Adding to 20120 its reverse (2102), we get a palindrome (22222).
The spelling of 20120 in words is "twenty thousand, one hundred twenty", and thus it is an iban number.