9988861 has 4 divisors (see below), whose sum is σ = 10077372. Its totient is φ = 9900352.

The previous prime is 9988817. The next prime is 9988873. The reversal of 9988861 is 1688899.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1688899 = 17 ⋅99347.

It can be written as a sum of positive squares in 2 ways, for example, as 1102500 + 8886361 = 1050^2 + 2981^2 .

It is a cyclic number.

It is not a de Polignac number, because 9988861 - 2⁷ = 9988733 is a prime.

It is a Duffinian number.

9988861 is a lucky number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9988361) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44086 + ... + 44311.

It is an arithmetic number, because the mean of its divisors is an integer number (2519343).

Almost surely, 2^9988861 is an apocalyptic number.

It is an amenable number.

9988861 is a deficient number, since it is larger than the sum of its proper divisors (88511).

9988861 is a wasteful number, since it uses less digits than its factorization.

9988861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88510.

The product of its digits is 248832, while the sum is 49.

The square root of 9988861 is about 3160.5159388935. The cubic root of 9988861 is about 215.3634451229.

The spelling of 9988861 in words is "nine million, nine hundred eighty-eight thousand, eight hundred sixty-one".