21010020113 has 2 divisors, whose sum is σ = 21010020114. Its totient is φ = 21010020112.

The previous prime is 21010020091. The next prime is 21010020131. The reversal of 21010020113 is 31102001012.

Together with next prime (21010020131) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19537609729 + 1472410384 = 139777^2 + 38372^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010020113 - 2¹⁰ = 21010019089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21010020094 and 21010020103.

It is not a weakly prime, because it can be changed into another prime (21010020173) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505010056 + 10505010057.

It is an arithmetic number, because the mean of its divisors is an integer number (10505010057).

Almost surely, 2^21010020113 is an apocalyptic number.

It is an amenable number.

21010020113 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010020113 is an equidigital number, since it uses as much as digits as its factorization.

21010020113 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12, while the sum is 11.

Adding to 21010020113 its reverse (31102001012), we get a palindrome (52112021125).

The spelling of 21010020113 in words is "twenty-one billion, ten million, twenty thousand, one hundred thirteen".