20001222021 has 16 divisors (see below), whose sum is σ = 29186247168. Its totient is φ = 12082969200.

The previous prime is 20001222013. The next prime is 20001222047. The reversal of 20001222021 is 12022210002.

It is not a de Polignac number, because 20001222021 - 2³ = 20001222013 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20001221988 and 20001222006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001222091) 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, 964171 + ... + 984696.

It is an arithmetic number, because the mean of its divisors is an integer number (1824140448).

Almost surely, 2^20001222021 is an apocalyptic number.

It is an amenable number.

20001222021 is a deficient number, since it is larger than the sum of its proper divisors (9185025147).

20001222021 is a wasteful number, since it uses less digits than its factorization.

20001222021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1949192.

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

Adding to 20001222021 its reverse (12022210002), we get a palindrome (32023432023).

The spelling of 20001222021 in words is "twenty billion, one million, two hundred twenty-two thousand, twenty-one".