999916644 has 12 divisors (see below), whose sum is σ = 2333138864. Its totient is φ = 333305544.

The previous prime is 999916637. The next prime is 999916649. The reversal of 999916644 is 446619999.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (999916649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41663182 + ... + 41663205.

Almost surely, 2^999916644 is an apocalyptic number.

It is an amenable number.

999916644 is an abundant number, since it is smaller than the sum of its proper divisors (1333222220).

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

999916644 is a wasteful number, since it uses less digits than its factorization.

999916644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83326394 (or 83326392 counting only the distinct ones).

The product of its digits is 3779136, while the sum is 57.

The square root of 999916644 is about 31621.4586001342. The cubic root of 999916644 is about 999.9722138946.

The spelling of 999916644 in words is "nine hundred ninety-nine million, nine hundred sixteen thousand, six hundred forty-four".