1979805 has 16 divisors (see below), whose sum is σ = 3205440. Its totient is φ = 1043328.

The previous prime is 1979779. The next prime is 1979807. The reversal of 1979805 is 5089791.

It is a happy number.

It is not a de Polignac number, because 1979805 - 2⁵ = 1979773 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1979807) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 594 + ... + 2076.

It is an arithmetic number, because the mean of its divisors is an integer number (200340).

2^1979805 is an apocalyptic number.

1979805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1979805 is a deficient number, since it is larger than the sum of its proper divisors (1225635).

1979805 is a wasteful number, since it uses less digits than its factorization.

1979805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1580.

The product of its (nonzero) digits is 22680, while the sum is 39.

The square root of 1979805 is about 1407.0554360081. The cubic root of 1979805 is about 125.5666011578.

The spelling of 1979805 in words is "one million, nine hundred seventy-nine thousand, eight hundred five".