20012220 has 72 divisors (see below), whose sum is σ = 61575696. Its totient is φ = 5260032.

The previous prime is 20012219. The next prime is 20012261. The reversal of 20012220 is 2221002.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 12379 + ... + 13901.

It is an arithmetic number, because the mean of its divisors is an integer number (855218).

Almost surely, 2^20012220 is an apocalyptic number.

20012220 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 20012220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30787848).

20012220 is an abundant number, since it is smaller than the sum of its proper divisors (41563476).

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

20012220 is a wasteful number, since it uses less digits than its factorization.

20012220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1611 (or 1606 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

The square root of 20012220 is about 4473.5019839048. The cubic root of 20012220 is about 271.4970340427.

Adding to 20012220 its reverse (2221002), we get a palindrome (22233222).

The spelling of 20012220 in words is "twenty million, twelve thousand, two hundred twenty".