999888665 has 8 divisors (see below), whose sum is σ = 1216303368. Its totient is φ = 788952960.

The previous prime is 999888613. The next prime is 999888667. The reversal of 999888665 is 566888999.

It can be written as a sum of positive squares in 4 ways, for example, as 1024 + 999887641 = 32^2 + 31621^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 999888665 - 2²² = 995694361 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 999888595 and 999888604.

It is not an unprimeable number, because it can be changed into a prime (999888667) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1369346 + ... + 1370075.

It is an arithmetic number, because the mean of its divisors is an integer number (152037921).

Almost surely, 2^999888665 is an apocalyptic number.

It is an amenable number.

999888665 is a deficient number, since it is larger than the sum of its proper divisors (216414703).

999888665 is a wasteful number, since it uses less digits than its factorization.

999888665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2739499.

The product of its digits is 67184640, while the sum is 68.

The square root of 999888665 is about 31621.0161917671. The cubic root of 999888665 is about 999.9628869560.

The spelling of 999888665 in words is "nine hundred ninety-nine million, eight hundred eighty-eight thousand, six hundred sixty-five".