21220220201 has 4 divisors (see below), whose sum is σ = 21220716804. Its totient is φ = 21219723600.

The previous prime is 21220220173. The next prime is 21220220237. The reversal of 21220220201 is 10202202212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3749725225 + 17470494976 = 61235^2 + 132176^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220220201 - 2⁶ = 21220220137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21220220251) 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, 177470 + ... + 271911.

It is an arithmetic number, because the mean of its divisors is an integer number (5305179201).

Almost surely, 2^21220220201 is an apocalyptic number.

It is an amenable number.

21220220201 is a deficient number, since it is larger than the sum of its proper divisors (496603).

21220220201 is an equidigital number, since it uses as much as digits as its factorization.

21220220201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 496602.

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

Adding to 21220220201 its reverse (10202202212), we get a palindrome (31422422413).

The spelling of 21220220201 in words is "twenty-one billion, two hundred twenty million, two hundred twenty thousand, two hundred one".