1980805 has 8 divisors (see below), whose sum is σ = 2385144. Its totient is φ = 1579200.

The previous prime is 1980791. The next prime is 1980809. The reversal of 1980805 is 5080891.

It can be written as a sum of positive squares in 4 ways, for example, as 1156 + 1979649 = 34^2 + 1407^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1980805 - 2⁵ = 1980773 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 (1980809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1635 + ... + 2575.

It is an arithmetic number, because the mean of its divisors is an integer number (298143).

2^1980805 is an apocalyptic number.

It is an amenable number.

1980805 is a deficient number, since it is larger than the sum of its proper divisors (404339).

1980805 is an equidigital number, since it uses as much as digits as its factorization.

1980805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1367.

The product of its (nonzero) digits is 2880, while the sum is 31.

The square root of 1980805 is about 1407.4107431734. The cubic root of 1980805 is about 125.5877388399.

The spelling of 1980805 in words is "one million, nine hundred eighty thousand, eight hundred five".