991830 has 32 divisors (see below), whose sum is σ = 2721024. Its totient is φ = 226656.

The previous prime is 991817. The next prime is 991867. The reversal of 991830 is 38199.

It is a happy number.

991830 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

991830 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2152 + ... + 2571.

It is an arithmetic number, because the mean of its divisors is an integer number (85032).

2⁹⁹¹⁸³⁰ is an apocalyptic number.

991830 is an abundant number, since it is smaller than the sum of its proper divisors (1729194).

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

991830 is a wasteful number, since it uses less digits than its factorization.

991830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4740.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 991830 is about 995.9066221288. The cubic root of 991830 is about 99.7269216275.

The spelling of 991830 in words is "nine hundred ninety-one thousand, eight hundred thirty".