991589472 has 96 divisors (see below), whose sum is σ = 2898655200. Its totient is φ = 329785344.

The previous prime is 991589419. The next prime is 991589483. The reversal of 991589472 is 274985199.

991589472 is a `hidden beast` number, since 9 + 91 + 5 + 89 + 472 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (54).

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, 490608 + ... + 492624.

It is an arithmetic number, because the mean of its divisors is an integer number (30194325).

Almost surely, 2^991589472 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 991589472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1449327600).

991589472 is an abundant number, since it is smaller than the sum of its proper divisors (1907065728).

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

991589472 is a wasteful number, since it uses less digits than its factorization.

991589472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2605 (or 2591 counting only the distinct ones).

The product of its digits is 1632960, while the sum is 54.

The square root of 991589472 is about 31489.5136831295. The cubic root of 991589472 is about 997.1885940705.

The spelling of 991589472 in words is "nine hundred ninety-one million, five hundred eighty-nine thousand, four hundred seventy-two".