20013220 has 48 divisors (see below), whose sum is σ = 44311680. Its totient is φ = 7577856.

The previous prime is 20013193. The next prime is 20013221. The reversal of 20013220 is 2231002.

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 = 20013197 and 20013206.

It is not an unprimeable number, because it can be changed into a prime (20013221) 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, 63784 + ... + 64096.

It is an arithmetic number, because the mean of its divisors is an integer number (923160).

Almost surely, 2^20013220 is an apocalyptic number.

20013220 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 20013220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22155840).

20013220 is an abundant number, since it is smaller than the sum of its proper divisors (24298460).

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

20013220 is a wasteful number, since it uses less digits than its factorization.

20013220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 484 (or 482 counting only the distinct ones).

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

The square root of 20013220 is about 4473.6137517671. The cubic root of 20013220 is about 271.5015561549.

Adding to 20013220 its reverse (2231002), we get a palindrome (22244222).

The spelling of 20013220 in words is "twenty million, thirteen thousand, two hundred twenty".