991683 has 48 divisors (see below), whose sum is σ = 1886976. Its totient is φ = 505440.

The previous prime is 991663. The next prime is 991693. The reversal of 991683 is 386199.

991683 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 991683 - 2⁵ = 991651 is a prime.

It is not an unprimeable number, because it can be changed into a prime (991603) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 18685 + ... + 18737.

It is an arithmetic number, because the mean of its divisors is an integer number (39312).

2⁹⁹¹⁶⁸³ is an apocalyptic number.

991683 is a deficient number, since it is larger than the sum of its proper divisors (895293).

991683 is a wasteful number, since it uses less digits than its factorization.

991683 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86 (or 74 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 991683 is about 995.8328172941. The cubic root of 991683 is about 99.7219945124.

It can be divided in two parts, 9916 and 83, that added together give a palindrome (9999).

The spelling of 991683 in words is "nine hundred ninety-one thousand, six hundred eighty-three".