20201222221221 has 4 divisors (see below), whose sum is σ = 26934962961632. Its totient is φ = 13467481480812.

The previous prime is 20201222221183. The next prime is 20201222221241. The reversal of 20201222221221 is 12212222210202.

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 not a de Polignac number, because 20201222221221 - 2⁶ = 20201222221157 is a prime.

It is a super-2 number, since 2×20201222221221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20201222221241) 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, 3366870370201 + ... + 3366870370206.

It is an arithmetic number, because the mean of its divisors is an integer number (6733740740408).

Almost surely, 2^{20201222221221} is an apocalyptic number.

It is an amenable number.

20201222221221 is a deficient number, since it is larger than the sum of its proper divisors (6733740740411).

20201222221221 is an equidigital number, since it uses as much as digits as its factorization.

20201222221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6733740740410.

The product of its (nonzero) digits is 512, while the sum is 21.

Adding to 20201222221221 its reverse (12212222210202), we get a palindrome (32413444431423).

The spelling of 20201222221221 in words is "twenty trillion, two hundred one billion, two hundred twenty-two million, two hundred twenty-one thousand, two hundred twenty-one".