999988 has 12 divisors (see below), whose sum is σ = 1909152. Its totient is φ = 454520.

The previous prime is 999983. The next prime is 1000003. The reversal of 999988 is 889999.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11320 + ... + 11407.

It is an arithmetic number, because the mean of its divisors is an integer number (159096).

2⁹⁹⁹⁹⁸⁸ is an apocalyptic number.

It is an amenable number.

999988 is a deficient number, since it is larger than the sum of its proper divisors (909164).

999988 is a wasteful number, since it uses less digits than its factorization.

999988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22742 (or 22740 counting only the distinct ones).

The product of its digits is 419904, while the sum is 52.

The square root of 999988 is about 999.9939999820. The cubic root of 999988 is about 99.9995999984. Note that the first 3 decimals are identical.

The spelling of 999988 in words is "nine hundred ninety-nine thousand, nine hundred eighty-eight".