2100181 has 2 divisors, whose sum is σ = 2100182.
Its totient is φ = 2100180.
The previous prime is 2100173. The next prime is 2100191. The reversal of 2100181 is 1810012.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 1343281 + 756900 = 1159^2 + 870^2
It is a cyclic number.
It is not a de Polignac number, because 2100181 - 23 = 2100173 is a prime.
It is a super-2 number, since 2×21001812 = 8821520465522, which contains 22 as substring.
2100181 is a lucky number.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (2100121) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050090 + 1050091.
It is an arithmetic number, because the mean of its divisors is an integer number (1050091).
22100181 is an apocalyptic number.
It is an amenable number.
2100181 is a deficient number, since it is larger than the sum of its proper divisors (1).
2100181 is an equidigital number, since it uses as much as digits as its factorization.
2100181 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 2100181 is about 1449.2001242065.
The cubic root of 2100181 is about 128.0615955173.
Adding to 2100181 its reverse (1810012), we get a palindrome (3910193).
The spelling of 2100181 in words is "two million, one hundred thousand, one hundred eighty-one".