21010100101 has 2 divisors, whose sum is σ = 21010100102. Its totient is φ = 21010100100.

The previous prime is 21010100087. The next prime is 21010100179. The reversal of 21010100101 is 10100101012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11615450625 + 9394649476 = 107775^2 + 96926^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010100101 - 2⁹ = 21010099589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21010100201) 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, 10505050050 + 10505050051.

It is an arithmetic number, because the mean of its divisors is an integer number (10505050051).

Almost surely, 2^21010100101 is an apocalyptic number.

It is an amenable number.

21010100101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010100101 is an equidigital number, since it uses as much as digits as its factorization.

21010100101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2, while the sum is 7.

Adding to 21010100101 its reverse (10100101012), we get a palindrome (31110201113).

The spelling of 21010100101 in words is "twenty-one billion, ten million, one hundred thousand, one hundred one".