999647 has 8 divisors (see below), whose sum is σ = 1148160. Its totient is φ = 860760.

The previous prime is 999631. The next prime is 999653. The reversal of 999647 is 746999.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 999647 - 2⁴ = 999631 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 999598 and 999607.

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 999647.

It is not an unprimeable number, because it can be changed into a prime (999667) 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, 2183 + ... + 2600.

It is an arithmetic number, because the mean of its divisors is an integer number (143520).

2⁹⁹⁹⁶⁴⁷ is an apocalyptic number.

999647 is a deficient number, since it is larger than the sum of its proper divisors (148513).

999647 is a wasteful number, since it uses less digits than its factorization.

999647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4813.

The product of its digits is 122472, while the sum is 44.

The square root of 999647 is about 999.8234844211. The cubic root of 999647 is about 99.9882319485.

The spelling of 999647 in words is "nine hundred ninety-nine thousand, six hundred forty-seven".