1987679 has 2 divisors, whose sum is σ = 1987680. Its totient is φ = 1987678.

The previous prime is 1987673. The next prime is 1987681. The reversal of 1987679 is 9767891.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1987679 is a prime.

Together with 1987681, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1987673) 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 as a sum of consecutive naturals, namely, 993839 + 993840.

It is an arithmetic number, because the mean of its divisors is an integer number (993840).

2^1987679 is an apocalyptic number.

1987679 is a deficient number, since it is larger than the sum of its proper divisors (1).

1987679 is an equidigital number, since it uses as much as digits as its factorization.

1987679 is an odious number, because the sum of its binary digits is odd.

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

The square root of 1987679 is about 1409.8507013156. The cubic root of 1987679 is about 125.7328470847.

The spelling of 1987679 in words is "one million, nine hundred eighty-seven thousand, six hundred seventy-nine".