999997 has 4 divisors (see below), whose sum is σ = 1002076. Its totient is φ = 997920.

The previous prime is 999983. The next prime is 1000003. The reversal of 999997 is 799999.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 793881 + 206116 = 891^2 + 454^2 .

It is a cyclic number.

It is not a de Polignac number, because 999997 - 2¹¹ = 997949 is a prime.

It is an Ulam number.

It is a Duffinian 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 (999907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 97 + ... + 1417.

It is an arithmetic number, because the mean of its divisors is an integer number (250519).

2⁹⁹⁹⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

999997 is a deficient number, since it is larger than the sum of its proper divisors (2079).

999997 is a wasteful number, since it uses less digits than its factorization.

999997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2078.

The product of its digits is 413343, while the sum is 52.

The square root of 999997 is about 999.9984999989. The cubic root of 999997 is about 99.9998999999. Note that the first 3 decimals are identical.

The spelling of 999997 in words is "nine hundred ninety-nine thousand, nine hundred ninety-seven".