991296000 has 240 divisors, whose sum is σ = 3572536968. Its totient is φ = 264192000.

The previous prime is 991295867. The next prime is 991296041. The reversal of 991296000 is 692199.

It can be written as a sum of positive squares in 4 ways, for example, as 408363264 + 582932736 = 20208^2 + 24144^2 .

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 575140 + ... + 576860.

Almost surely, 2^991296000 is an apocalyptic number.

991296000 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 991296000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1786268484).

991296000 is an abundant number, since it is smaller than the sum of its proper divisors (2581240968).

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

991296000 is a wasteful number, since it uses less digits than its factorization.

991296000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1760 (or 1731 counting only the distinct ones).

The product of its (nonzero) digits is 8748, while the sum is 36.

The square root of 991296000 is about 31484.8535013266. The cubic root of 991296000 is about 997.0902079894.

The spelling of 991296000 in words is "nine hundred ninety-one million, two hundred ninety-six thousand".