999663616 has 96 divisors (see below), whose sum is σ = 2309973120. Its totient is φ = 423641088.

The previous prime is 999663589. The next prime is 999663619. The reversal of 999663616 is 616366999.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (999663619) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1476270 + ... + 1476946.

It is an arithmetic number, because the mean of its divisors is an integer number (24062220).

Almost surely, 2^999663616 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 999663616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1154986560).

999663616 is an abundant number, since it is smaller than the sum of its proper divisors (1310309504).

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

999663616 is a wasteful number, since it uses less digits than its factorization.

999663616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 809 (or 789 counting only the distinct ones).

The product of its digits is 2834352, while the sum is 55.

The square root of 999663616 is about 31617.4574562851. The cubic root of 999663616 is about 999.8878594250.

The spelling of 999663616 in words is "nine hundred ninety-nine million, six hundred sixty-three thousand, six hundred sixteen".