2100205 has 4 divisors (see below), whose sum is σ = 2520252. Its totient is φ = 1680160.

The previous prime is 2100193. The next prime is 2100221. The reversal of 2100205 is 5020012.

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 946729 + 1153476 = 973^2 + 1074^2 .

It is not a de Polignac number, because 2100205 - 2⁵ = 2100173 is a prime.

It is a super-2 number, since 2×2100205² = 8821722084050, which contains 22 as substring.

It is a Duffinian number.

2100205 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2100191 and 2100200.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 210016 + ... + 210025.

It is an arithmetic number, because the mean of its divisors is an integer number (630063).

2^2100205 is an apocalyptic number.

It is an amenable number.

2100205 is a deficient number, since it is larger than the sum of its proper divisors (420047).

2100205 is an equidigital number, since it uses as much as digits as its factorization.

2100205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420046.

The product of its (nonzero) digits is 20, while the sum is 10.

The square root of 2100205 is about 1449.2084046127. The cubic root of 2100205 is about 128.0620833271.

Adding to 2100205 its product of nonzero digits (20), we get a triangular number (2100225 = T₂₀₄₉).

Adding to 2100205 its reverse (5020012), we get a palindrome (7120217).

The spelling of 2100205 in words is "two million, one hundred thousand, two hundred five".