Search a number
BaseRepresentation
bin100110001001…
…011000001001
3200211001020222
4212021120021
510024444011
6554155425
7150666113
oct46113011
920731228
109999881
115710071
123422b75
1320c17b8
1414843b3
15d27ddb
hex989609

9999881 has 4 divisors (see below), whose sum is σ = 10188612. Its totient is φ = 9811152.

The previous prime is 9999877. The next prime is 9999883. The reversal of 9999881 is 1889999.

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

It can be written as a sum of positive squares in 2 ways, for example, as 8462281 + 1537600 = 2909^2 + 1240^2 .

It is a cyclic number.

It is not a de Polignac number, because 9999881 - 22 = 9999877 is a prime.

It is a super-2 number, since 2×99998812 = 199995240028322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (53), and also a Moran number because the ratio is a prime number: 188677 = 9999881 / (9 + 9 + 9 + 9 + 8 + 8 + 1).

It is a Duffinian number.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (9999883) 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, 94286 + ... + 94391.

It is an arithmetic number, because the mean of its divisors is an integer number (2547153).

Almost surely, 29999881 is an apocalyptic number.

It is an amenable number.

9999881 is a deficient number, since it is larger than the sum of its proper divisors (188731).

9999881 is a wasteful number, since it uses less digits than its factorization.

9999881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188730.

The product of its digits is 419904, while the sum is 53.

The square root of 9999881 is about 3162.2588445603. The cubic root of 9999881 is about 215.4426144074.

The spelling of 9999881 in words is "nine million, nine hundred ninety-nine thousand, eight hundred eighty-one".

Divisors: 1 53 188677 9999881