1989665158823 has 4 divisors (see below), whose sum is σ = 1991830192560. Its totient is φ = 1987500125088.

The previous prime is 1989665158807. The next prime is 1989665158907. The reversal of 1989665158823 is 3288515669891.

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 1989665158823 - 2⁴ = 1989665158807 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1989665154823) 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, 1082515490 + ... + 1082517327.

It is an arithmetic number, because the mean of its divisors is an integer number (497957548140).

Almost surely, 2^{1989665158823} is an apocalyptic number.

1989665158823 is a deficient number, since it is larger than the sum of its proper divisors (2165033737).

1989665158823 is an equidigital number, since it uses as much as digits as its factorization.

1989665158823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2165033736.

The product of its digits is 223948800, while the sum is 71.

The spelling of 1989665158823 in words is "one trillion, nine hundred eighty-nine billion, six hundred sixty-five million, one hundred fifty-eight thousand, eight hundred twenty-three".