2101 has 4 divisors (see below), whose sum is σ = 2304.
Its totient is φ = 1900.
The previous prime is 2099. The next prime is 2111. The reversal of 2101 is 1012.
Adding to 2101 its reverse (1012), we get a palindrome (3113).
Subtracting from 2101 its reverse (1012), we obtain a square (1089 = 332).
Multipling 2101 by its reverse (1012), we get a palindrome (2126212).
It can be divided in two parts, 2 and 101, that multiplied together give a palindrome (202).
2101 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, and also a Blum integer, because the two primes are equal to 3 mod 4.
It is a cyclic number.
It is not a de Polignac number, because 2101 - 21 = 2099 is a prime.
It is an alternating number because its digits alternate between even and odd.
It is a Duffinian number.
It is a nialpdrome in base 14 and base 15.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (2111) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (5) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85 + ... + 106.
It is an arithmetic number, because the mean of its divisors is an integer number (576).
22101 is an apocalyptic number.
2101 is the 25-th centered heptagonal number and also the 21-st centered decagonal number.
It is an amenable number.
2101 is a deficient number, since it is larger than the sum of its proper divisors (203).
2101 is a wasteful number, since it uses less digits than its factorization.
2101 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 202.
The product of its (nonzero) digits is 2, while the sum is 4.
The square root of 2101 is about 45.8366665455.
The cubic root of 2101 is about 12.8078239927.
The spelling of 2101 in words is "two thousand, one hundred one", and thus it is an iban number.