991115097 has 16 divisors (see below), whose sum is σ = 1519006080. Its totient is φ = 563075712.

The previous prime is 991115093. The next prime is 991115243. The reversal of 991115097 is 790511199.

It is a happy number.

It is not a de Polignac number, because 991115097 - 2² = 991115093 is a prime.

It is not an unprimeable number, because it can be changed into a prime (991115093) 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 15 ways as a sum of consecutive naturals, for example, 132772 + ... + 140037.

It is an arithmetic number, because the mean of its divisors is an integer number (94937880).

Almost surely, 2^991115097 is an apocalyptic number.

It is an amenable number.

991115097 is a deficient number, since it is larger than the sum of its proper divisors (527890983).

991115097 is a wasteful number, since it uses less digits than its factorization.

991115097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272992.

The product of its (nonzero) digits is 25515, while the sum is 42.

The square root of 991115097 is about 31481.9805126679. The cubic root of 991115097 is about 997.0295508351.

The spelling of 991115097 in words is "nine hundred ninety-one million, one hundred fifteen thousand, ninety-seven".