1989326823491 has 32 divisors (see below), whose sum is σ = 2292891245568. Its totient is φ = 1690675459200.

The previous prime is 1989326823461. The next prime is 1989326823493. The reversal of 1989326823491 is 1943286239891.

It is a de Polignac number, because none of the positive numbers 2^k-1989326823491 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1989326823493) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 794775746 + ... + 794778248.

It is an arithmetic number, because the mean of its divisors is an integer number (71652851424).

Almost surely, 2^{1989326823491} is an apocalyptic number.

1989326823491 is a deficient number, since it is larger than the sum of its proper divisors (303564422077).

1989326823491 is a wasteful number, since it uses less digits than its factorization.

1989326823491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4451.

The product of its digits is 40310784, while the sum is 65.

The spelling of 1989326823491 in words is "one trillion, nine hundred eighty-nine billion, three hundred twenty-six million, eight hundred twenty-three thousand, four hundred ninety-one".