991284 has 24 divisors (see below), whose sum is σ = 2643648. Its totient is φ = 283200.

The previous prime is 991273. The next prime is 991313. The reversal of 991284 is 482199.

It is a congruent number.

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, 5817 + ... + 5984.

It is an arithmetic number, because the mean of its divisors is an integer number (110152).

2⁹⁹¹²⁸⁴ is an apocalyptic number.

It is an amenable number.

991284 is an abundant number, since it is smaller than the sum of its proper divisors (1652364).

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

991284 is a wasteful number, since it uses less digits than its factorization.

991284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11815 (or 11813 counting only the distinct ones).

The product of its digits is 5184, while the sum is 33.

The square root of 991284 is about 995.6324623073. The cubic root of 991284 is about 99.7086184593.

It can be divided in two parts, 991 and 284, that added together give a triangular number (1275 = T₅₀).

The spelling of 991284 in words is "nine hundred ninety-one thousand, two hundred eighty-four".