1999974989 has 4 divisors (see below), whose sum is σ = 2001577500. Its totient is φ = 1998372480.

The previous prime is 1999974967. The next prime is 1999975001. The reversal of 1999974989 is 9894799991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9894799991 = 7517 ⋅1316323.

It can be written as a sum of positive squares in 2 ways, for example, as 892216900 + 1107758089 = 29870^2 + 33283^2 .

It is a cyclic number.

It is not a de Polignac number, because 1999974989 - 2²⁸ = 1731539533 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999974089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 799382 + ... + 801879.

It is an arithmetic number, because the mean of its divisors is an integer number (500394375).

Almost surely, 2^1999974989 is an apocalyptic number.

It is an amenable number.

1999974989 is a deficient number, since it is larger than the sum of its proper divisors (1602511).

1999974989 is a wasteful number, since it uses less digits than its factorization.

1999974989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1602510.

The product of its digits is 119042784, while the sum is 74.

The square root of 1999974989 is about 44721.0799176406. The cubic root of 1999974989 is about 1259.9157978921.

The spelling of 1999974989 in words is "one billion, nine hundred ninety-nine million, nine hundred seventy-four thousand, nine hundred eighty-nine".