20021221002000 has 160 divisors (see below), whose sum is σ = 64631935255680. Its totient is φ = 5332084185600.

The previous prime is 20021221001923. The next prime is 20021221002023. The reversal of 20021221002000 is 20012212002.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2479611 + ... + 6796389.

It is an arithmetic number, because the mean of its divisors is an integer number (403949595348).

Almost surely, 2^{20021221002000} is an apocalyptic number.

20021221002000 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 20021221002000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32315967627840).

20021221002000 is an abundant number, since it is smaller than the sum of its proper divisors (44610714253680).

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

20021221002000 is a wasteful number, since it uses less digits than its factorization.

20021221002000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4317578 (or 4317562 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

Adding to 20021221002000 its reverse (20012212002), we get a palindrome (20041233214002).

The spelling of 20021221002000 in words is "twenty trillion, twenty-one billion, two hundred twenty-one million, two thousand".