991552000 has 80 divisors (see below), whose sum is σ = 2472656472. Its totient is φ = 396595200.

The previous prime is 991551971. The next prime is 991552027. The reversal of 991552000 is 255199.

It can be written as a sum of positive squares in 4 ways, for example, as 79995136 + 911556864 = 8944^2 + 30192^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56254 + ... + 71746.

Almost surely, 2^991552000 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 991552000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1236328236).

991552000 is an abundant number, since it is smaller than the sum of its proper divisors (1481104472).

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

991552000 is an equidigital number, since it uses as much as digits as its factorization.

991552000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15526 (or 15500 counting only the distinct ones).

The product of its (nonzero) digits is 4050, while the sum is 31.

The square root of 991552000 is about 31488.9186857853. The cubic root of 991552000 is about 997.1760327156.

The spelling of 991552000 in words is "nine hundred ninety-one million, five hundred fifty-two thousand".