115551 has 12 divisors (see below), whose sum is σ = 171912. Its totient is φ = 74736.

The previous prime is 115547. The next prime is 115553. The reversal of 115551 is 155511.

115551 is a `hidden beast` number, since 115 + 551 = 666.

It is not a de Polignac number, because 115551 - 2² = 115547 is a prime.

115551 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (115553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 160 + ... + 506.

It is an arithmetic number, because the mean of its divisors is an integer number (14326).

2¹¹⁵⁵⁵¹ is an apocalyptic number.

115551 is a deficient number, since it is larger than the sum of its proper divisors (56361).

115551 is a wasteful number, since it uses less digits than its factorization.

115551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390 (or 387 counting only the distinct ones).

The product of its digits is 125, while the sum is 18.

The square root of 115551 is about 339.9279335389. The cubic root of 115551 is about 48.7069837505.

It can be divided in two parts, 115 and 551, that added together give a palindrome (666).

The spelling of 115551 in words is "one hundred fifteen thousand, five hundred fifty-one".