2121212101 has 2 divisors, whose sum is σ = 2121212102. Its totient is φ = 2121212100.

The previous prime is 2121212089. The next prime is 2121212147. The reversal of 2121212101 is 1012121212.

2121212101 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1359396900 + 761815201 = 36870^2 + 27601^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2121212101 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121218101) 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, 1060606050 + 1060606051.

It is an arithmetic number, because the mean of its divisors is an integer number (1060606051).

Almost surely, 2^2121212101 is an apocalyptic number.

It is an amenable number.

2121212101 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121212101 is an equidigital number, since it uses as much as digits as its factorization.

2121212101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 2121212101 is about 46056.6184277569. The cubic root of 2121212101 is about 1284.8764386331.

Adding to 2121212101 its reverse (1012121212), we get a palindrome (3133333313).

It can be divided in two parts, 2121212 and 101, that multiplied together give a palindrome (214242412).

The spelling of 2121212101 in words is "two billion, one hundred twenty-one million, two hundred twelve thousand, one hundred one".