1989659 has 4 divisors (see below), whose sum is σ = 2273904. Its totient is φ = 1705416.

The previous prime is 1989643. The next prime is 1989671. The reversal of 1989659 is 9569891.

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

It is a cyclic number.

It is not a de Polignac number, because 1989659 - 2⁴ = 1989643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1989619) 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, 142112 + ... + 142125.

It is an arithmetic number, because the mean of its divisors is an integer number (568476).

2^1989659 is an apocalyptic number.

1989659 is a deficient number, since it is larger than the sum of its proper divisors (284245).

1989659 is an equidigital number, since it uses as much as digits as its factorization.

1989659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284244.

The product of its digits is 174960, while the sum is 47.

The square root of 1989659 is about 1410.5527285430. The cubic root of 1989659 is about 125.7745822642.

The spelling of 1989659 in words is "one million, nine hundred eighty-nine thousand, six hundred fifty-nine".