2100001 has 2 divisors, whose sum is σ = 2100002.
Its totient is φ = 2100000.
The previous prime is 2099963. The next prime is 2100011. The reversal of 2100001 is 1000012.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 2099601 + 400 = 1449^2 + 20^2
It is a cyclic number.
It is not a de Polignac number, because 2100001 - 213 = 2091809 is a prime.
It is a Chen prime.
It is not a weakly prime, because it can be changed into another prime (2100011) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050000 + 1050001.
It is an arithmetic number, because the mean of its divisors is an integer number (1050001).
22100001 is an apocalyptic number.
It is an amenable number.
2100001 is a deficient number, since it is larger than the sum of its proper divisors (1).
2100001 is an equidigital number, since it uses as much as digits as its factorization.
2100001 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 2, while the sum is 4.
The square root of 2100001 is about 1449.1380196517.
The cubic root of 2100001 is about 128.0579368254.
Adding to 2100001 its reverse (1000012), we get a palindrome (3100013).
Multiplying 2100001 by its reverse (1000012), we get a palindrome (2100026200012).
It can be divided in two parts, 2 and 100001, that multiplied together give a palindrome (200002).
The spelling of 2100001 in words is "two million, one hundred thousand, one".