20111220061 has 2 divisors, whose sum is σ = 20111220062. Its totient is φ = 20111220060.

The previous prime is 20111220007. The next prime is 20111220089. The reversal of 20111220061 is 16002211102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13104525625 + 7006694436 = 114475^2 + 83706^2 .

It is a cyclic number.

It is not a de Polignac number, because 20111220061 - 2³³ = 11521285469 is a prime.

It is a super-2 number, since 2×20111220061² (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 (20111220161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055610030 + 10055610031.

It is an arithmetic number, because the mean of its divisors is an integer number (10055610031).

Almost surely, 2^20111220061 is an apocalyptic number.

It is an amenable number.

20111220061 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111220061 is an equidigital number, since it uses as much as digits as its factorization.

20111220061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 20111220061 its reverse (16002211102), we get a palindrome (36113431163).

The spelling of 20111220061 in words is "twenty billion, one hundred eleven million, two hundred twenty thousand, sixty-one".