21011112061 has 2 divisors, whose sum is σ = 21011112062. Its totient is φ = 21011112060.

The previous prime is 21011112047. The next prime is 21011112071. The reversal of 21011112061 is 16021111012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16504540900 + 4506571161 = 128470^2 + 67131^2 .

It is a cyclic number.

It is not a de Polignac number, because 21011112061 - 2¹⁷ = 21010980989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011112011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505556030 + 10505556031.

It is an arithmetic number, because the mean of its divisors is an integer number (10505556031).

Almost surely, 2^21011112061 is an apocalyptic number.

It is an amenable number.

21011112061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011112061 is an equidigital number, since it uses as much as digits as its factorization.

21011112061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 16.

Adding to 21011112061 its reverse (16021111012), we get a palindrome (37032223073).

The spelling of 21011112061 in words is "twenty-one billion, eleven million, one hundred twelve thousand, sixty-one".