1980205 has 4 divisors (see below), whose sum is σ = 2376252. Its totient is φ = 1584160.

The previous prime is 1980191. The next prime is 1980221. The reversal of 1980205 is 5020891.

1980205 is nontrivially palindromic in base 4.

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 1532644 + 447561 = 1238^2 + 669^2 .

It is not a de Polignac number, because 1980205 - 2¹¹ = 1978157 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1980205.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 198016 + ... + 198025.

It is an arithmetic number, because the mean of its divisors is an integer number (594063).

2^1980205 is an apocalyptic number.

It is an amenable number.

1980205 is a deficient number, since it is larger than the sum of its proper divisors (396047).

1980205 is an equidigital number, since it uses as much as digits as its factorization.

1980205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396046.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 1980205 is about 1407.1975696397. The cubic root of 1980205 is about 125.5750570846.

It can be divided in two parts, 198020 and 5, that added together give a square (198025 = 445²).

The spelling of 1980205 in words is "one million, nine hundred eighty thousand, two hundred five".