999000000644 has 48 divisors (see below), whose sum is σ = 1774272331776. Its totient is φ = 492132564000.

The previous prime is 999000000643. The next prime is 999000000667. The reversal of 999000000644 is 446000000999.

It is not an unprimeable number, because it can be changed into a prime (999000000643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46691189 + ... + 46712579.

It is an arithmetic number, because the mean of its divisors is an integer number (36964006912).

Almost surely, 2^999000000644 is an apocalyptic number.

It is an amenable number.

999000000644 is a deficient number, since it is larger than the sum of its proper divisors (775272331132).

999000000644 is a wasteful number, since it uses less digits than its factorization.

999000000644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22176 (or 22174 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 41.

The spelling of 999000000644 in words is "nine hundred ninety-nine billion, six hundred forty-four", and thus it is an aban number.