991047187200 has 864 divisors, whose sum is σ = 3878282329600. Its totient is φ = 222721228800.

The previous prime is 991047187183. The next prime is 991047187213. The reversal of 991047187200 is 2781740199.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 991047187200.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 401720367 + ... + 401722833.

Almost surely, 2^991047187200 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 991047187200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1939141164800).

991047187200 is an abundant number, since it is smaller than the sum of its proper divisors (2887235142400).

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

991047187200 is a wasteful number, since it uses less digits than its factorization.

991047187200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2578 (or 2545 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 48.

The spelling of 991047187200 in words is "nine hundred ninety-one billion, forty-seven million, one hundred eighty-seven thousand, two hundred".