1989943279 has 16 divisors (see below), whose sum is σ = 2200670208. Its totient is φ = 1789777792.

The previous prime is 1989943273. The next prime is 1989943297. The reversal of 1989943279 is 9723499891.

It is a cyclic number.

It is not a de Polignac number, because 1989943279 - 2³ = 1989943271 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 (1989943271) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 626754 + ... + 629920.

It is an arithmetic number, because the mean of its divisors is an integer number (137541888).

Almost surely, 2^1989943279 is an apocalyptic number.

1989943279 is a deficient number, since it is larger than the sum of its proper divisors (210726929).

1989943279 is a wasteful number, since it uses less digits than its factorization.

1989943279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4814.

The product of its digits is 8817984, while the sum is 61.

The square root of 1989943279 is about 44608.7802904316. The cubic root of 1989943279 is about 1257.8057212980.

The spelling of 1989943279 in words is "one billion, nine hundred eighty-nine million, nine hundred forty-three thousand, two hundred seventy-nine".