991206049080 has 512 divisors, whose sum is σ = 3352559616000. Its totient is φ = 232794777600.

The previous prime is 991206049003. The next prime is 991206049147. The reversal of 991206049080 is 80940602199.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1222201875 + ... + 1222202685.

It is an arithmetic number, because the mean of its divisors is an integer number (6547968000).

Almost surely, 2^991206049080 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 991206049080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1676279808000).

991206049080 is an abundant number, since it is smaller than the sum of its proper divisors (2361353566920).

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

991206049080 is a wasteful number, since it uses less digits than its factorization.

991206049080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1195 (or 1191 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 48.

The spelling of 991206049080 in words is "nine hundred ninety-one billion, two hundred six million, forty-nine thousand, eighty".