113128181 has 4 divisors (see below), whose sum is σ = 114248364. Its totient is φ = 112008000.

The previous prime is 113128177. The next prime is 113128199. The reversal of 113128181 is 181821311.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 109537156 + 3591025 = 10466^2 + 1895^2 .

It is a cyclic number.

It is not a de Polignac number, because 113128181 - 2² = 113128177 is a prime.

It is a super-2 number, since 2×113128181² = 25595970672737522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 113128181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (113128121) 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 3 ways as a sum of consecutive naturals, for example, 559940 + ... + 560141.

It is an arithmetic number, because the mean of its divisors is an integer number (28562091).

Almost surely, 2^113128181 is an apocalyptic number.

It is an amenable number.

113128181 is a deficient number, since it is larger than the sum of its proper divisors (1120183).

113128181 is a wasteful number, since it uses less digits than its factorization.

113128181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1120182.

The product of its digits is 384, while the sum is 26.

The square root of 113128181 is about 10636.1732310075. The cubic root of 113128181 is about 483.6415466845.

Adding to 113128181 its reverse (181821311), we get a palindrome (294949492).

The spelling of 113128181 in words is "one hundred thirteen million, one hundred twenty-eight thousand, one hundred eighty-one".