20111012221 has 2 divisors, whose sum is σ = 20111012222. Its totient is φ = 20111012220.

The previous prime is 20111012197. The next prime is 20111012239. The reversal of 20111012221 is 12221011102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20089944121 + 21068100 = 141739^2 + 4590^2 .

It is a cyclic number.

It is not a de Polignac number, because 20111012221 - 2³¹ = 17963528573 is a prime.

It is a super-2 number, since 2×20111012221² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20111012281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055506110 + 10055506111.

It is an arithmetic number, because the mean of its divisors is an integer number (10055506111).

Almost surely, 2^20111012221 is an apocalyptic number.

It is an amenable number.

20111012221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111012221 is an equidigital number, since it uses as much as digits as its factorization.

20111012221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 20111012221 its reverse (12221011102), we get a palindrome (32332023323).

The spelling of 20111012221 in words is "twenty billion, one hundred eleven million, twelve thousand, two hundred twenty-one".