20011101221 has 4 divisors (see below), whose sum is σ = 20476475712. Its totient is φ = 19545726732.

The previous prime is 20011101203. The next prime is 20011101239. The reversal of 20011101221 is 12210111002.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12210111002 = 2 ⋅6105055501.

It is an interprime number because it is at equal distance from previous prime (20011101203) and next prime (20011101239).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20011101221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20011106221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 232687181 + ... + 232687266.

It is an arithmetic number, because the mean of its divisors is an integer number (5119118928).

Almost surely, 2^20011101221 is an apocalyptic number.

It is an amenable number.

20011101221 is a deficient number, since it is larger than the sum of its proper divisors (465374491).

20011101221 is an equidigital number, since it uses as much as digits as its factorization.

20011101221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 465374490.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 20011101221 its reverse (12210111002), we get a palindrome (32221212223).

The spelling of 20011101221 in words is "twenty billion, eleven million, one hundred one thousand, two hundred twenty-one".