991232000 has 204 divisors, whose sum is σ = 2719461108. Its totient is φ = 360448000.

The previous prime is 991231999. The next prime is 991232003. The reversal of 991232000 is 232199.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 2 ways, for example, as 31719424 + 959512576 = 5632^2 + 30976^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991232003) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 90111995 + ... + 90112005.

Almost surely, 2^991232000 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 991232000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1359730554).

991232000 is an abundant number, since it is smaller than the sum of its proper divisors (1728229108).

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

991232000 is an frugal number, since it uses more digits than its factorization.

991232000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69 (or 18 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 26.

The square root of 991232000 is about 31483.8371231970. The cubic root of 991232000 is about 997.0687494992.

Adding to 991232000 its reverse (232199), we get a palindrome (991464199).

The spelling of 991232000 in words is "nine hundred ninety-one million, two hundred thirty-two thousand".