509115981 has 16 divisors (see below), whose sum is σ = 741040128. Its totient is φ = 308343600.

The previous prime is 509115973. The next prime is 509116031. The reversal of 509115981 is 189511905.

It is not a de Polignac number, because 509115981 - 2³ = 509115973 is a prime.

It is a super-2 number, since 2×509115981² = 518398164219184722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (509113981) 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 15 ways as a sum of consecutive naturals, for example, 53236 + ... + 62066.

It is an arithmetic number, because the mean of its divisors is an integer number (46315008).

Almost surely, 2^509115981 is an apocalyptic number.

It is an amenable number.

509115981 is a deficient number, since it is larger than the sum of its proper divisors (231924147).

509115981 is a wasteful number, since it uses less digits than its factorization.

509115981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10592.

The product of its (nonzero) digits is 16200, while the sum is 39.

The square root of 509115981 is about 22563.5985826729. The cubic root of 509115981 is about 798.4950775566.

The spelling of 509115981 in words is "five hundred nine million, one hundred fifteen thousand, nine hundred eighty-one".