21068101 has 2 divisors, whose sum is σ = 21068102. Its totient is φ = 21068100.

The previous prime is 21068087. The next prime is 21068149. The reversal of 21068101 is 10186012.

It is a Cunningham number, because it is equal to 4590²+1.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21068100 + 1 = 4590^2 + 1^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21068101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21062101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10534050 + 10534051.

It is an arithmetic number, because the mean of its divisors is an integer number (10534051).

Almost surely, 2^21068101 is an apocalyptic number.

It is an amenable number.

21068101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21068101 is an equidigital number, since it uses as much as digits as its factorization.

21068101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 19.

The square root of 21068101 is about 4590.0001089325. Note that the first 3 decimals coincide. The cubic root of 21068101 is about 276.1903267845.

The spelling of 21068101 in words is "twenty-one million, sixty-eight thousand, one hundred one".