1979842 has 4 divisors (see below), whose sum is σ = 2969766. Its totient is φ = 989920.

The previous prime is 1979827. The next prime is 1979891. The reversal of 1979842 is 2489791.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2489791 = 1193 ⋅2087.

It can be written as a sum of positive squares in only one way, i.e., 1718721 + 261121 = 1311^2 + 511^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 1979795 and 1979804.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 494959 + ... + 494962.

2^1979842 is an apocalyptic number.

1979842 is a deficient number, since it is larger than the sum of its proper divisors (989924).

1979842 is an equidigital number, since it uses as much as digits as its factorization.

1979842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 989923.

The product of its digits is 36288, while the sum is 40.

The square root of 1979842 is about 1407.0685839717. The cubic root of 1979842 is about 125.5673833789.

The spelling of 1979842 in words is "one million, nine hundred seventy-nine thousand, eight hundred forty-two".