991247000 has 64 divisors (see below), whose sum is σ = 2328955200. Its totient is φ = 394886400.

The previous prime is 991246957. The next prime is 991247021. The reversal of 991247000 is 742199.

991247000 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 261116 + ... + 264884.

It is an arithmetic number, because the mean of its divisors is an integer number (36389925).

Almost surely, 2^991247000 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 991247000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1164477600).

991247000 is an abundant number, since it is smaller than the sum of its proper divisors (1337708200).

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

991247000 is a wasteful number, since it uses less digits than its factorization.

991247000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4053 (or 4039 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 991247000 is about 31484.0753397650. The cubic root of 991247000 is about 997.0737789157.

Adding to 991247000 its reverse (742199), we get a palindrome (991989199).

The spelling of 991247000 in words is "nine hundred ninety-one million, two hundred forty-seven thousand".