1985979 has 4 divisors (see below), whose sum is σ = 2647976. Its totient is φ = 1323984.

The previous prime is 1985939. The next prime is 1985987. The reversal of 1985979 is 9795891.

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

It is not a de Polignac number, because 1985979 - 2¹¹ = 1983931 is a prime.

It is a super-2 number, since 2×1985979² = 7888225176882, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1985939) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 330994 + ... + 330999.

It is an arithmetic number, because the mean of its divisors is an integer number (661994).

2^1985979 is an apocalyptic number.

1985979 is a deficient number, since it is larger than the sum of its proper divisors (661997).

1985979 is an equidigital number, since it uses as much as digits as its factorization.

1985979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661996.

The product of its digits is 204120, while the sum is 48.

The square root of 1985979 is about 1409.2476716319. The cubic root of 1985979 is about 125.6969917302.

The spelling of 1985979 in words is "one million, nine hundred eighty-five thousand, nine hundred seventy-nine".