20212112221 has 4 divisors (see below), whose sum is σ = 23099556832. Its totient is φ = 17324667612.

The previous prime is 20212112213. The next prime is 20212112257. The reversal of 20212112221 is 12221121202.

It is a happy number.

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 20212112221 - 2³ = 20212112213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20212112195 and 20212112204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20212112521) 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, 1443722295 + ... + 1443722308.

It is an arithmetic number, because the mean of its divisors is an integer number (5774889208).

Almost surely, 2^20212112221 is an apocalyptic number.

It is an amenable number.

20212112221 is a deficient number, since it is larger than the sum of its proper divisors (2887444611).

20212112221 is an equidigital number, since it uses as much as digits as its factorization.

20212112221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2887444610.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 20212112221 its reverse (12221121202), we get a palindrome (32433233423).

The spelling of 20212112221 in words is "twenty billion, two hundred twelve million, one hundred twelve thousand, two hundred twenty-one".