9998665 has 4 divisors (see below), whose sum is σ = 11998404. Its totient is φ = 7998928.

The previous prime is 9998641. The next prime is 9998689. The reversal of 9998665 is 5668999.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (9998641) and next prime (9998689).

It can be written as a sum of positive squares in 2 ways, for example, as 5626384 + 4372281 = 2372^2 + 2091^2 .

It is a cyclic number.

It is not a de Polignac number, because 9998665 - 2⁵ = 9998633 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 999862 + ... + 999871.

It is an arithmetic number, because the mean of its divisors is an integer number (2999601).

Almost surely, 2^9998665 is an apocalyptic number.

It is an amenable number.

9998665 is a deficient number, since it is larger than the sum of its proper divisors (1999739).

9998665 is a wasteful number, since it uses less digits than its factorization.

9998665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1999738.

The product of its digits is 1049760, while the sum is 52.

The square root of 9998665 is about 3162.0665710892. The cubic root of 9998665 is about 215.4338813422.

The spelling of 9998665 in words is "nine million, nine hundred ninety-eight thousand, six hundred sixty-five".