1989318786 has 64 divisors (see below), whose sum is σ = 4904272128. Its totient is φ = 523853568.

The previous prime is 1989318781. The next prime is 1989318803. The reversal of 1989318786 is 6878139891.

It is not an unprimeable number, because it can be changed into a prime (1989318781) 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 in 31 ways as a sum of consecutive naturals, for example, 410916 + ... + 415728.

It is an arithmetic number, because the mean of its divisors is an integer number (76629252).

Almost surely, 2^1989318786 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1989318786, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2452136064).

1989318786 is an abundant number, since it is smaller than the sum of its proper divisors (2914953342).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1989318786 is a wasteful number, since it uses less digits than its factorization.

1989318786 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5595.

The product of its digits is 5225472, while the sum is 60.

The square root of 1989318786 is about 44601.7800765844. The cubic root of 1989318786 is about 1257.6741307715.

The spelling of 1989318786 in words is "one billion, nine hundred eighty-nine million, three hundred eighteen thousand, seven hundred eighty-six".