20021220000 has 180 divisors, whose sum is σ = 71147045970. Its totient is φ = 5338944000.

The previous prime is 20021219983. The next prime is 20021220007. The reversal of 20021220000 is 2212002.

It can be written as a sum of positive squares in 5 ways, for example, as 305690256 + 19715529744 = 17484^2 + 140412^2 .

It is a tau number, because it is divible by the number of its divisors (180).

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

It is not an unprimeable number, because it can be changed into a prime (20021220007) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 124386 + ... + 235614.

Almost surely, 2^20021220000 is an apocalyptic number.

20021220000 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 20021220000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35573522985).

20021220000 is an abundant number, since it is smaller than the sum of its proper divisors (51125825970).

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

20021220000 is a wasteful number, since it uses less digits than its factorization.

20021220000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111265 (or 111239 counting only the distinct ones).

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

Adding to 20021220000 its reverse (2212002), we get a palindrome (20023432002).

The spelling of 20021220000 in words is "twenty billion, twenty-one million, two hundred twenty thousand".