2128205 has 4 divisors (see below), whose sum is σ = 2553852. Its totient is φ = 1702560.

The previous prime is 2128201. The next prime is 2128241. The reversal of 2128205 is 5028212.

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 1085764 + 1042441 = 1042^2 + 1021^2 .

It is not a de Polignac number, because 2128205 - 2² = 2128201 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2128201) 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, 212816 + ... + 212825.

It is an arithmetic number, because the mean of its divisors is an integer number (638463).

2^2128205 is an apocalyptic number.

It is an amenable number.

2128205 is a deficient number, since it is larger than the sum of its proper divisors (425647).

2128205 is an equidigital number, since it uses as much as digits as its factorization.

2128205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425646.

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 2128205 is about 1458.8368654514. The cubic root of 2128205 is about 128.6286820260.

The spelling of 2128205 in words is "two million, one hundred twenty-eight thousand, two hundred five".