999973 has 12 divisors (see below), whose sum is σ = 1111908. Its totient is φ = 898560.

The previous prime is 999961. The next prime is 999979. The reversal of 999973 is 379999.

It can be written as a sum of positive squares in 6 ways, for example, as 432964 + 567009 = 658^2 + 753^2 .

It is a de Polignac number, because none of the positive numbers 2^k-999973 is a prime.

999973 is a lucky number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999979) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10261 + ... + 10357.

It is an arithmetic number, because the mean of its divisors is an integer number (92659).

2⁹⁹⁹⁹⁷³ is an apocalyptic number.

It is an amenable number.

999973 is a deficient number, since it is larger than the sum of its proper divisors (111935).

999973 is a wasteful number, since it uses less digits than its factorization.

999973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184 (or 171 counting only the distinct ones).

The product of its digits is 137781, while the sum is 46.

The square root of 999973 is about 999.9864999089. The cubic root of 999973 is about 99.9990999919. Note that the first 3 decimals are identical.

It can be divided in two parts, 99997 and 3, that added together give a 5-th power (100000 = 10⁵).

The spelling of 999973 in words is "nine hundred ninety-nine thousand, nine hundred seventy-three".