991768707072 has 1152 divisors, whose sum is σ = 3562180614720. Its totient is φ = 273277255680.

The previous prime is 991768707067. The next prime is 991768707119. The reversal of 991768707072 is 270707867199.

It is a tau number, because it is divible by the number of its divisors (1152).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 14802517983 + ... + 14802518049.

Almost surely, 2^991768707072 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991768707072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1781090307360).

991768707072 is an abundant number, since it is smaller than the sum of its proper divisors (2570411907648).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

991768707072 is an equidigital number, since it uses as much as digits as its factorization.

991768707072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149 (or 96 counting only the distinct ones).

The product of its (nonzero) digits is 18670176, while the sum is 63.

The spelling of 991768707072 in words is "nine hundred ninety-one billion, seven hundred sixty-eight million, seven hundred seven thousand, seventy-two".