991794915 has 32 divisors (see below), whose sum is σ = 1765412160. Its totient is φ = 528291072.

The previous prime is 991794857. The next prime is 991794917. The reversal of 991794915 is 519497199.

It is not a de Polignac number, because 991794915 - 2⁸ = 991794659 is a prime.

It is not an unprimeable number, because it can be changed into a prime (991794917) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 114207 + ... + 122583.

It is an arithmetic number, because the mean of its divisors is an integer number (55169130).

Almost surely, 2^991794915 is an apocalyptic number.

991794915 is a deficient number, since it is larger than the sum of its proper divisors (773617245).

991794915 is a wasteful number, since it uses less digits than its factorization.

991794915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9268 (or 9262 counting only the distinct ones).

The product of its digits is 918540, while the sum is 54.

The square root of 991794915 is about 31492.7756001277. The cubic root of 991794915 is about 997.2574570006.

The spelling of 991794915 in words is "nine hundred ninety-one million, seven hundred ninety-four thousand, nine hundred fifteen".