20031220 has 48 divisors (see below), whose sum is σ = 46484928. Its totient is φ = 7189760.

The previous prime is 20031217. The next prime is 20031223. The reversal of 20031220 is 2213002.

It is an interprime number because it is at equal distance from previous prime (20031217) and next prime (20031223).

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 20031197 and 20031206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20031223) 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, 17712 + ... + 18808.

It is an arithmetic number, because the mean of its divisors is an integer number (968436).

Almost surely, 2^20031220 is an apocalyptic number.

20031220 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 20031220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23242464).

20031220 is an abundant number, since it is smaller than the sum of its proper divisors (26453708).

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

20031220 is a wasteful number, since it uses less digits than its factorization.

20031220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1200 (or 1198 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 10.

The square root of 20031220 is about 4475.6250960061. The cubic root of 20031220 is about 271.5829284278.

Adding to 20031220 its reverse (2213002), we get a palindrome (22244222).

It can be divided in two parts, 2003 and 1220, that added together give a palindrome (3223).

The spelling of 20031220 in words is "twenty million, thirty-one thousand, two hundred twenty".