Search a number
-
+
8981 = 71283
BaseRepresentation
bin10001100010101
3110022122
42030111
5241411
6105325
735120
oct21425
913278
108981
116825
125245
13411b
1433b7
1529db
hex2315

8981 has 4 divisors (see below), whose sum is σ = 10272. Its totient is φ = 7692.

The previous prime is 8971. The next prime is 8999. The reversal of 8981 is 1898.

It can be divided in two parts, 8 and 981, that added together give a palindrome (989).

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-8981 is a prime.

It is a super-2 number, since 2×89812 = 161316722, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 8981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8941) 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, 635 + ... + 648.

It is an arithmetic number, because the mean of its divisors is an integer number (2568).

28981 is an apocalyptic number.

It is an amenable number.

8981 is a deficient number, since it is larger than the sum of its proper divisors (1291).

8981 is a wasteful number, since it uses less digits than its factorization.

8981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1290.

The product of its digits is 576, while the sum is 26.

The square root of 8981 is about 94.7681381056. The cubic root of 8981 is about 20.7861902910.

The spelling of 8981 in words is "eight thousand, nine hundred eighty-one".

Divisors: 1 7 1283 8981