1679987 has 4 divisors (see below), whose sum is σ = 1682976. Its totient is φ = 1677000.

The previous prime is 1679981. The next prime is 1680013. The reversal of 1679987 is 7899761.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7899761 = 31 ⋅254831.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1679987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1679981) 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 3 ways as a sum of consecutive naturals, for example, 368 + ... + 1869.

It is an arithmetic number, because the mean of its divisors is an integer number (420744).

2^1679987 is an apocalyptic number.

1679987 is a deficient number, since it is larger than the sum of its proper divisors (2989).

1679987 is an equidigital number, since it uses as much as digits as its factorization.

1679987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2988.

The product of its digits is 190512, while the sum is 47.

The square root of 1679987 is about 1296.1431248130. The cubic root of 1679987 is about 118.8781324236.

The spelling of 1679987 in words is "one million, six hundred seventy-nine thousand, nine hundred eighty-seven".