1989267209 has 4 divisors (see below), whose sum is σ = 2057862660. Its totient is φ = 1920671760.

The previous prime is 1989267193. The next prime is 1989267211. The reversal of 1989267209 is 9027629891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9027629891 = 7 ⋅1289661413.

It can be written as a sum of positive squares in 2 ways, for example, as 499075600 + 1490191609 = 22340^2 + 38603^2 .

It is a cyclic number.

It is not a de Polignac number, because 1989267209 - 2⁴ = 1989267193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1989267239) 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, 34297682 + ... + 34297739.

It is an arithmetic number, because the mean of its divisors is an integer number (514465665).

Almost surely, 2^1989267209 is an apocalyptic number.

It is an amenable number.

1989267209 is a deficient number, since it is larger than the sum of its proper divisors (68595451).

1989267209 is an equidigital number, since it uses as much as digits as its factorization.

1989267209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68595450.

The product of its (nonzero) digits is 979776, while the sum is 53.

The square root of 1989267209 is about 44601.2018784248. The cubic root of 1989267209 is about 1257.6632614528.

The spelling of 1989267209 in words is "one billion, nine hundred eighty-nine million, two hundred sixty-seven thousand, two hundred nine".