212101 has 4 divisors (see below), whose sum is σ = 214092. Its totient is φ = 210112.

The previous prime is 212099. The next prime is 212117. The reversal of 212101 is 101212.

212101 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

212101 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 52900 + 159201 = 230^2 + 399^2 .

It is a cyclic number.

It is not a de Polignac number, because 212101 - 2¹ = 212099 is a prime.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 826 + ... + 1051.

It is an arithmetic number, because the mean of its divisors is an integer number (53523).

2²¹²¹⁰¹ is an apocalyptic number.

It is an amenable number.

212101 is a deficient number, since it is larger than the sum of its proper divisors (1991).

212101 is a wasteful number, since it uses less digits than its factorization.

212101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1990.

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 212101 is about 460.5442432601. The cubic root of 212101 is about 59.6367871925.

Adding to 212101 its reverse (101212), we get a palindrome (313313).

Subtracting from 212101 its reverse (101212), we obtain a square (110889 = 333²).

It can be divided in two parts, 212 and 101, that multiplied together give a palindrome (21412).

The spelling of 212101 in words is "two hundred twelve thousand, one hundred one", and thus it is an iban number.