999688388 has 12 divisors (see below), whose sum is σ = 1750688940. Its totient is φ = 499491552.

The previous prime is 999688387. The next prime is 999688427. The reversal of 999688388 is 883886999.

It can be written as a sum of positive squares in 2 ways, for example, as 599368324 + 400320064 = 24482^2 + 20008^2 .

It is not an unprimeable number, because it can be changed into a prime (999688387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81731 + ... + 93162.

It is an arithmetic number, because the mean of its divisors is an integer number (145890745).

Almost surely, 2^999688388 is an apocalyptic number.

It is an amenable number.

999688388 is a deficient number, since it is larger than the sum of its proper divisors (751000552).

999688388 is a wasteful number, since it uses less digits than its factorization.

999688388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176326 (or 176324 counting only the distinct ones).

The product of its digits is 53747712, while the sum is 68.

The square root of 999688388 is about 31617.8491994633. The cubic root of 999688388 is about 999.8961185423.

The spelling of 999688388 in words is "nine hundred ninety-nine million, six hundred eighty-eight thousand, three hundred eighty-eight".