115521551218 has 4 divisors (see below), whose sum is σ = 173282326830. Its totient is φ = 57760775608.

The previous prime is 115521551213. The next prime is 115521551221. The reversal of 115521551218 is 812155125511.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 812155125511 = 61 ⋅13314018451.

It can be written as a sum of positive squares in only one way, i.e., 78485703409 + 37035847809 = 280153^2 + 192447^2 .

It is not an unprimeable number, because it can be changed into a prime (115521551213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28880387803 + ... + 28880387806.

Almost surely, 2^115521551218 is an apocalyptic number.

115521551218 is a deficient number, since it is larger than the sum of its proper divisors (57760775612).

115521551218 is an equidigital number, since it uses as much as digits as its factorization.

115521551218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57760775611.

The product of its digits is 20000, while the sum is 37.

Adding to 115521551218 its reverse (812155125511), we get a palindrome (927676676729).

The spelling of 115521551218 in words is "one hundred fifteen billion, five hundred twenty-one million, five hundred fifty-one thousand, two hundred eighteen".