991616 has 32 divisors (see below), whose sum is σ = 2023680. Its totient is φ = 483840.

The previous prime is 991607. The next prime is 991619. The reversal of 991616 is 616199.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (32).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 991616.

It is not an unprimeable number, because it can be changed into a prime (991619) by changing a digit.

991616 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7745 + ... + 7871.

It is an arithmetic number, because the mean of its divisors is an integer number (63240).

2⁹⁹¹⁶¹⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1011840).

991616 is an abundant number, since it is smaller than the sum of its proper divisors (1032064).

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

991616 is a wasteful number, since it uses less digits than its factorization.

991616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202 (or 190 counting only the distinct ones).

The product of its digits is 2916, while the sum is 32.

The square root of 991616 is about 995.7991765411. The cubic root of 991616 is about 99.7197486589.

The spelling of 991616 in words is "nine hundred ninety-one thousand, six hundred sixteen".