991936000 has 160 divisors (see below), whose sum is σ = 2700228960. Its totient is φ = 360448000.

The previous prime is 991935979. The next prime is 991936003. The reversal of 991936000 is 639199.

It is a tau number, because it is divible by the number of its divisors (160).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991936003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 703296 + ... + 704704.

It is an arithmetic number, because the mean of its divisors is an integer number (16876431).

Almost surely, 2^991936000 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 991936000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1350114480).

991936000 is an abundant number, since it is smaller than the sum of its proper divisors (1708292960).

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

991936000 is a wasteful number, since it uses less digits than its factorization.

991936000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1453 (or 1427 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 37.

The square root of 991936000 is about 31495.0154786436. The cubic root of 991936000 is about 997.3047421114.

The spelling of 991936000 in words is "nine hundred ninety-one million, nine hundred thirty-six thousand".