1998679 has 2 divisors, whose sum is σ = 1998680. Its totient is φ = 1998678.

The previous prime is 1998643. The next prime is 1998691. The reversal of 1998679 is 9768991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1998679 - 2¹³ = 1990487 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1998379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999339 + 999340.

It is an arithmetic number, because the mean of its divisors is an integer number (999340).

2^1998679 is an apocalyptic number.

1998679 is a deficient number, since it is larger than the sum of its proper divisors (1).

1998679 is an equidigital number, since it uses as much as digits as its factorization.

1998679 is an evil number, because the sum of its binary digits is even.

The product of its digits is 244944, while the sum is 49.

The square root of 1998679 is about 1413.7464411980. The cubic root of 1998679 is about 125.9643596182.

The spelling of 1998679 in words is "one million, nine hundred ninety-eight thousand, six hundred seventy-nine".