20201221000 has 64 divisors (see below), whose sum is σ = 47294282880. Its totient is φ = 8076484800.

The previous prime is 20201220961. The next prime is 20201221003. The reversal of 20201221000 is 12210202.

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

It is not an unprimeable number, because it can be changed into a prime (20201221003) 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, 2799397 + ... + 2806603.

It is an arithmetic number, because the mean of its divisors is an integer number (738973170).

Almost surely, 2^20201221000 is an apocalyptic number.

20201221000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20201221000 is an abundant number, since it is smaller than the sum of its proper divisors (27093061880).

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

20201221000 is a wasteful number, since it uses less digits than its factorization.

20201221000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10031 (or 10017 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 20201221000 its reverse (12210202), we get a palindrome (20213431202).

The spelling of 20201221000 in words is "twenty billion, two hundred one million, two hundred twenty-one thousand".