21020026061 has 2 divisors, whose sum is σ = 21020026062. Its totient is φ = 21020026060.

The previous prime is 21020026043. The next prime is 21020026187. The reversal of 21020026061 is 16062002012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14431457161 + 6588568900 = 120131^2 + 81170^2 .

It is a cyclic number.

It is not a de Polignac number, because 21020026061 - 2⁶ = 21020025997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21020026361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510013030 + 10510013031.

It is an arithmetic number, because the mean of its divisors is an integer number (10510013031).

Almost surely, 2^21020026061 is an apocalyptic number.

It is an amenable number.

21020026061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020026061 is an equidigital number, since it uses as much as digits as its factorization.

21020026061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 21020026061 its reverse (16062002012), we get a palindrome (37082028073).

The spelling of 21020026061 in words is "twenty-one billion, twenty million, twenty-six thousand, sixty-one".