999866665 has 8 divisors (see below), whose sum is σ = 1371245760. Its totient is φ = 685622832.

The previous prime is 999866663. The next prime is 999866671. The reversal of 999866665 is 566668999.

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

It is a cyclic number.

It is not a de Polignac number, because 999866665 - 2¹ = 999866663 is a prime.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 999866597 and 999866606.

It is not an unprimeable number, because it can be changed into a prime (999866663) 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, 14283775 + ... + 14283844.

It is an arithmetic number, because the mean of its divisors is an integer number (171405720).

Almost surely, 2^999866665 is an apocalyptic number.

It is an amenable number.

999866665 is a deficient number, since it is larger than the sum of its proper divisors (371379095).

999866665 is a wasteful number, since it uses less digits than its factorization.

999866665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28567631.

The product of its digits is 37791360, while the sum is 64.

The square root of 999866665 is about 31620.6683199454. The cubic root of 999866665 is about 999.9555530245.

The spelling of 999866665 in words is "nine hundred ninety-nine million, eight hundred sixty-six thousand, six hundred sixty-five".