991325790000 has 1200 divisors, whose sum is σ = 4425860671232. Its totient is φ = 209112192000.

The previous prime is 991325789957. The next prime is 991325790031. The reversal of 991325790000 is 97523199.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (1200).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 221127759 + ... + 221132241.

Almost surely, 2^991325790000 is an apocalyptic number.

991325790000 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991325790000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2212930335616).

991325790000 is an abundant number, since it is smaller than the sum of its proper divisors (3434534881232).

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

991325790000 is a wasteful number, since it uses less digits than its factorization.

991325790000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4546 (or 4513 counting only the distinct ones).

The product of its (nonzero) digits is 153090, while the sum is 45.

The spelling of 991325790000 in words is "nine hundred ninety-one billion, three hundred twenty-five million, seven hundred ninety thousand".