509991889 has 9 divisors (see below), whose sum is σ = 560842779. Its totient is φ = 463403160.

The previous prime is 509991887. The next prime is 509991899. The reversal of 509991889 is 988199905.

It is a happy number.

The square root of 509991889 is 22583.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 263250625 + 246741264 = 16225^2 + 15708^2 .

It is not a de Polignac number, because 509991889 - 2¹ = 509991887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (509991887) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 247387 + ... + 249439.

Almost surely, 2^509991889 is an apocalyptic number.

509991889 is the 22583-rd square number.

509991889 is the 11292-nd centered octagonal number.

It is an amenable number.

509991889 is a deficient number, since it is larger than the sum of its proper divisors (50850890).

509991889 is an frugal number, since it uses more digits than its factorization.

509991889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4128 (or 2064 counting only the distinct ones).

The product of its (nonzero) digits is 2099520, while the sum is 58.

The cubic root of 509991889 is about 798.9527385066.

The spelling of 509991889 in words is "five hundred nine million, nine hundred ninety-one thousand, eight hundred eighty-nine".