2180405 has 4 divisors (see below), whose sum is σ = 2616492. Its totient is φ = 1744320.

The previous prime is 2180393. The next prime is 2180417. The reversal of 2180405 is 5040812.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (2180393) and next prime (2180417).

It can be written as a sum of positive squares in 2 ways, for example, as 1503076 + 677329 = 1226^2 + 823^2 .

It is not a de Polignac number, because 2180405 - 2⁴ = 2180389 is a prime.

It is a Duffinian number.

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, 218036 + ... + 218045.

It is an arithmetic number, because the mean of its divisors is an integer number (654123).

2^2180405 is an apocalyptic number.

It is an amenable number.

2180405 is a deficient number, since it is larger than the sum of its proper divisors (436087).

2180405 is an equidigital number, since it uses as much as digits as its factorization.

2180405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 436086.

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

The square root of 2180405 is about 1476.6194499599. The cubic root of 2180405 is about 129.6718548408.

The spelling of 2180405 in words is "two million, one hundred eighty thousand, four hundred five".