509781121058889 has 9 divisors (see below), whose sum is σ = 736350606035629. Its totient is φ = 339854035549260.

The previous prime is 509781121058879. The next prime is 509781121058893. The reversal of 509781121058889 is 988850121187905.

The square root of 509781121058889 is 22578333.

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

509781121058889 is a `hidden beast` number, since 5 + 0 + 9 + 7 + 8 + 11 + 21 + 0 + 588 + 8 + 9 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 509781121058889 - 2¹¹ = 509781121056841 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (509781121058879) 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, 63971944 + ... + 71498054.

Almost surely, 2^{509781121058889} is an apocalyptic number.

509781121058889 is the 22578333-rd square number.

509781121058889 is the 11289167-th centered octagonal number.

It is an amenable number.

509781121058889 is a deficient number, since it is larger than the sum of its proper divisors (226569484976740).

509781121058889 is an frugal number, since it uses more digits than its factorization.

509781121058889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15052228 (or 7526114 counting only the distinct ones).

The product of its (nonzero) digits is 116121600, while the sum is 72.

The spelling of 509781121058889 in words is "five hundred nine trillion, seven hundred eighty-one billion, one hundred twenty-one million, fifty-eight thousand, eight hundred eighty-nine".