21020012010061 has 2 divisors, whose sum is σ = 21020012010062. Its totient is φ = 21020012010060.

The previous prime is 21020012009999. The next prime is 21020012010083. The reversal of 21020012010061 is 16001021002012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15224581693161 + 5795430316900 = 3901869^2 + 2407370^2 .

It is a cyclic number.

It is not a de Polignac number, because 21020012010061 - 2⁷ = 21020012009933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21020012010161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510006005030 + 10510006005031.

It is an arithmetic number, because the mean of its divisors is an integer number (10510006005031).

Almost surely, 2^{21020012010061} is an apocalyptic number.

It is an amenable number.

21020012010061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020012010061 is an equidigital number, since it uses as much as digits as its factorization.

21020012010061 is an evil number, because the sum of its binary digits is even.

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

Adding to 21020012010061 its reverse (16001021002012), we get a palindrome (37021033012073).

The spelling of 21020012010061 in words is "twenty-one trillion, twenty billion, twelve million, ten thousand, sixty-one".