20002221221 has 4 divisors (see below), whose sum is σ = 20027637792. Its totient is φ = 19976804652.

The previous prime is 20002221209. The next prime is 20002221223. The reversal of 20002221221 is 12212220002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20002221221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20002221196 and 20002221205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20002221223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12707105 + ... + 12708678.

It is an arithmetic number, because the mean of its divisors is an integer number (5006909448).

Almost surely, 2^20002221221 is an apocalyptic number.

It is an amenable number.

20002221221 is a deficient number, since it is larger than the sum of its proper divisors (25416571).

20002221221 is an equidigital number, since it uses as much as digits as its factorization.

20002221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25416570.

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 20002221221 its reverse (12212220002), we get a palindrome (32214441223).

The spelling of 20002221221 in words is "twenty billion, two million, two hundred twenty-one thousand, two hundred twenty-one".