991481 has 8 divisors (see below), whose sum is σ = 1036800. Its totient is φ = 946960.

The previous prime is 991453. The next prime is 991483. The reversal of 991481 is 184199.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-991481 is a prime.

It is a super-2 number, since 2×991481² = 1966069146722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991483) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 5096 + ... + 5286.

It is an arithmetic number, because the mean of its divisors is an integer number (129600).

2⁹⁹¹⁴⁸¹ is an apocalyptic number.

It is an amenable number.

991481 is a deficient number, since it is larger than the sum of its proper divisors (45319).

991481 is a wasteful number, since it uses less digits than its factorization.

991481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399.

The product of its digits is 2592, while the sum is 32.

The square root of 991481 is about 995.7313894821. The cubic root of 991481 is about 99.7152231245.

Subtracting from 991481 its product of digits (2592), we obtain a palindrome (988889).

The spelling of 991481 in words is "nine hundred ninety-one thousand, four hundred eighty-one".