991582 has 4 divisors (see below), whose sum is σ = 1487376. Its totient is φ = 495790.

The previous prime is 991579. The next prime is 991603. The reversal of 991582 is 285199.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 247894 + ... + 247897.

It is an arithmetic number, because the mean of its divisors is an integer number (371844).

2⁹⁹¹⁵⁸² is an apocalyptic number.

991582 is a deficient number, since it is larger than the sum of its proper divisors (495794).

991582 is a wasteful number, since it uses less digits than its factorization.

991582 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 495793.

The product of its digits is 6480, while the sum is 34.

The square root of 991582 is about 995.7821046795. The cubic root of 991582 is about 99.7186089334.

It can be divided in two parts, 99 and 1582, that added together give a square (1681 = 41²).

The spelling of 991582 in words is "nine hundred ninety-one thousand, five hundred eighty-two".