999996644 has 18 divisors (see below), whose sum is σ = 1858992450. Its totient is φ = 470586112.

The previous prime is 999996643. The next prime is 999996649. The reversal of 999996644 is 446699999.

It can be written as a sum of positive squares in 3 ways, for example, as 512116900 + 487879744 = 22630^2 + 22088^2 .

It is a super-2 number, since 2×999996644² = 1999986576022525472, which contains 22 as substring.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (999996643) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 431369 + ... + 433680.

Almost surely, 2^999996644 is an apocalyptic number.

It is an amenable number.

999996644 is a deficient number, since it is larger than the sum of its proper divisors (858995806).

999996644 is a wasteful number, since it uses less digits than its factorization.

999996644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 865087 (or 865068 counting only the distinct ones).

The product of its digits is 34012224, while the sum is 65.

The square root of 999996644 is about 31622.7235386201. The cubic root of 999996644 is about 999.9988813321.

The spelling of 999996644 in words is "nine hundred ninety-nine million, nine hundred ninety-six thousand, six hundred forty-four".