20021221011 has 128 divisors (see below), whose sum is σ = 32550958080. Its totient is φ = 10809344000.

The previous prime is 20021220953. The next prime is 20021221027. The reversal of 20021221011 is 11012212002.

It is a cyclic number.

It is not a de Polignac number, because 20021221011 - 2¹⁴ = 20021204627 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20021221091) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 177178891 + ... + 177179003.

It is an arithmetic number, because the mean of its divisors is an integer number (254304360).

Almost surely, 2^20021221011 is an apocalyptic number.

20021221011 is a deficient number, since it is larger than the sum of its proper divisors (12529737069).

20021221011 is a wasteful number, since it uses less digits than its factorization.

20021221011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 357.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 20021221011 its reverse (11012212002), we get a palindrome (31033433013).

Subtracting from 20021221011 its reverse (11012212002), we obtain a palindrome (9009009009).

The spelling of 20021221011 in words is "twenty billion, twenty-one million, two hundred twenty-one thousand, eleven".