9998888665 has 4 divisors (see below), whose sum is σ = 11998666404. Its totient is φ = 7999110928.

The previous prime is 9998888659. The next prime is 9998888671. The reversal of 9998888665 is 5668888999.

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 (9998888659) and next prime (9998888671).

It can be written as a sum of positive squares in 2 ways, for example, as 3532638096 + 6466250569 = 59436^2 + 80413^2 .

It is a cyclic number.

It is not a de Polignac number, because 9998888665 - 2²⁵ = 9965334233 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 = 9998888591 and 9998888600.

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, 999888862 + ... + 999888871.

It is an arithmetic number, because the mean of its divisors is an integer number (2999666601).

Almost surely, 2^9998888665 is an apocalyptic number.

It is an amenable number.

9998888665 is a deficient number, since it is larger than the sum of its proper divisors (1999777739).

9998888665 is a wasteful number, since it uses less digits than its factorization.

9998888665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1999777738.

The product of its digits is 537477120, while the sum is 76.

The square root of 9998888665 is about 99994.4431706082. The cubic root of 9998888665 is about 2154.3548771193.

The spelling of 9998888665 in words is "nine billion, nine hundred ninety-eight million, eight hundred eighty-eight thousand, six hundred sixty-five".