991236329127 has 48 divisors (see below), whose sum is σ = 1573222839552. Its totient is φ = 596421692160.

The previous prime is 991236329053. The next prime is 991236329131. The reversal of 991236329127 is 721923632199.

991236329127 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-991236329127 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991236329177) 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, 13636543 + ... + 13709039.

It is an arithmetic number, because the mean of its divisors is an integer number (32775475824).

Almost surely, 2^991236329127 is an apocalyptic number.

991236329127 is a deficient number, since it is larger than the sum of its proper divisors (581986510425).

991236329127 is a wasteful number, since it uses less digits than its factorization.

991236329127 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73508 (or 73505 counting only the distinct ones).

The product of its digits is 2204496, while the sum is 54.

The spelling of 991236329127 in words is "nine hundred ninety-one billion, two hundred thirty-six million, three hundred twenty-nine thousand, one hundred twenty-seven".