115651612221 has 48 divisors (see below), whose sum is σ = 172583611200. Its totient is φ = 68698361088.

The previous prime is 115651612157. The next prime is 115651612229. The reversal of 115651612221 is 122216156511.

It is a happy number.

It is not a de Polignac number, because 115651612221 - 2⁶ = 115651612157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (115651612229) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 80931135 + ... + 80932563.

It is an arithmetic number, because the mean of its divisors is an integer number (3595491900).

Almost surely, 2^115651612221 is an apocalyptic number.

It is an amenable number.

115651612221 is a deficient number, since it is larger than the sum of its proper divisors (56931998979).

115651612221 is an frugal number, since it uses more digits than its factorization.

115651612221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1536 (or 1468 counting only the distinct ones).

The product of its digits is 7200, while the sum is 33.

Adding to 115651612221 its reverse (122216156511), we get a palindrome (237867768732).

The spelling of 115651612221 in words is "one hundred fifteen billion, six hundred fifty-one million, six hundred twelve thousand, two hundred twenty-one".