115681509 has 12 divisors (see below), whose sum is σ = 167193676. Its totient is φ = 77075712.

The previous prime is 115681483. The next prime is 115681529. The reversal of 115681509 is 905186511.

It can be written as a sum of positive squares in 2 ways, for example, as 85045284 + 30636225 = 9222^2 + 5535^2 .

It is not a de Polignac number, because 115681509 - 2¹² = 115677413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (115681529) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20859 + ... + 25815.

Almost surely, 2^115681509 is an apocalyptic number.

It is an amenable number.

115681509 is a deficient number, since it is larger than the sum of its proper divisors (51512167).

115681509 is a wasteful number, since it uses less digits than its factorization.

115681509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7556 (or 7553 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 36.

The square root of 115681509 is about 10755.5338779625. The cubic root of 115681509 is about 487.2531420795.

The spelling of 115681509 in words is "one hundred fifteen million, six hundred eighty-one thousand, five hundred nine".