991651915948 has 24 divisors (see below), whose sum is σ = 1838679342192. Its totient is φ = 466353268224.

The previous prime is 991651915889. The next prime is 991651915949. The reversal of 991651915948 is 849519156199.

It is not an unprimeable number, because it can be changed into a prime (991651915949) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4684065 + ... + 4891192.

It is an arithmetic number, because the mean of its divisors is an integer number (76611639258).

Almost surely, 2^991651915948 is an apocalyptic number.

It is an amenable number.

991651915948 is a deficient number, since it is larger than the sum of its proper divisors (847027426244).

991651915948 is a wasteful number, since it uses less digits than its factorization.

991651915948 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9576801 (or 9576799 counting only the distinct ones).

The product of its digits is 31492800, while the sum is 67.

The spelling of 991651915948 in words is "nine hundred ninety-one billion, six hundred fifty-one million, nine hundred fifteen thousand, nine hundred forty-eight".