1999889249 has 2 divisors, whose sum is σ = 1999889250. Its totient is φ = 1999889248.

The previous prime is 1999889237. The next prime is 1999889321. The reversal of 1999889249 is 9429889991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1737222400 + 262666849 = 41680^2 + 16207^2 .

It is a cyclic number.

It is not a de Polignac number, because 1999889249 - 2²⁰ = 1998840673 is a prime.

It is not a weakly prime, because it can be changed into another prime (1999189249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999944624 + 999944625.

It is an arithmetic number, because the mean of its divisors is an integer number (999944625).

Almost surely, 2^1999889249 is an apocalyptic number.

It is an amenable number.

1999889249 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999889249 is an equidigital number, since it uses as much as digits as its factorization.

1999889249 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30233088, while the sum is 68.

The square root of 1999889249 is about 44720.1212990305. The cubic root of 1999889249 is about 1259.8977932129.

The spelling of 1999889249 in words is "one billion, nine hundred ninety-nine million, eight hundred eighty-nine thousand, two hundred forty-nine".