999897 has 4 divisors (see below), whose sum is σ = 1333200. Its totient is φ = 666596.

The previous prime is 999883. The next prime is 999907. The reversal of 999897 is 798999.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 798999 = 3 ⋅266333.

It is a cyclic number.

It is not a de Polignac number, because 999897 - 2⁷ = 999769 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (997897) 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, 166647 + ... + 166652.

It is an arithmetic number, because the mean of its divisors is an integer number (333300).

2⁹⁹⁹⁸⁹⁷ is an apocalyptic number.

It is an amenable number.

999897 is a deficient number, since it is larger than the sum of its proper divisors (333303).

999897 is a wasteful number, since it uses less digits than its factorization.

999897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333302.

The product of its digits is 367416, while the sum is 51.

The square root of 999897 is about 999.9484986738. The cubic root of 999897 is about 99.9965665488.

The spelling of 999897 in words is "nine hundred ninety-nine thousand, eight hundred ninety-seven".