20112021221 has 4 divisors (see below), whose sum is σ = 20114526732. Its totient is φ = 20109515712.

The previous prime is 20112021203. The next prime is 20112021253. The reversal of 20112021221 is 12212021102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12212021102 = 2 ⋅6106010551.

It can be written as a sum of positive squares in 2 ways, for example, as 15021198721 + 5090822500 = 122561^2 + 71350^2 .

It is a cyclic number.

It is not a de Polignac number, because 20112021221 - 2⁶ = 20112021157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20112021196 and 20112021205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20112021821) 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, 1240676 + ... + 1256781.

It is an arithmetic number, because the mean of its divisors is an integer number (5028631683).

Almost surely, 2^20112021221 is an apocalyptic number.

It is an amenable number.

20112021221 is a deficient number, since it is larger than the sum of its proper divisors (2505511).

20112021221 is an equidigital number, since it uses as much as digits as its factorization.

20112021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2505510.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 20112021221 its reverse (12212021102), we get a palindrome (32324042323).

The spelling of 20112021221 in words is "twenty billion, one hundred twelve million, twenty-one thousand, two hundred twenty-one".