1820205 has 32 divisors (see below), whose sum is σ = 3292800. Its totient is φ = 953856.

The previous prime is 1820201. The next prime is 1820213. The reversal of 1820205 is 5020281.

It is not a de Polignac number, because 1820205 - 2² = 1820201 is a prime.

1820205 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1820201) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13026 + ... + 13164.

It is an arithmetic number, because the mean of its divisors is an integer number (102900).

2^1820205 is an apocalyptic number.

1820205 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1820205 is a deficient number, since it is larger than the sum of its proper divisors (1472595).

1820205 is a wasteful number, since it uses less digits than its factorization.

1820205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250 (or 244 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 1820205 is about 1349.1497322388. The cubic root of 1820205 is about 122.0974988772.

Adding to 1820205 its reverse (5020281), we get a palindrome (6840486).

It can be divided in two parts, 1820 and 205, that added together give a square (2025 = 45²).

The spelling of 1820205 in words is "one million, eight hundred twenty thousand, two hundred five".