Search a number
13181 = 72269
BaseRepresentation
bin11001101111101
3200002012
43031331
5410211
6141005
753300
oct31575
920065
1013181
1199a3
127765
135ccc
144b37
153d8b
hex337d

13181 has 6 divisors (see below), whose sum is σ = 15390. Its totient is φ = 11256.

The previous prime is 13177. The next prime is 13183. The reversal of 13181 is 18131.

It can be written as a sum of positive squares in only one way, i.e., 8281 + 4900 = 91^2 + 70^2 .

It is not a de Polignac number, because 13181 - 22 = 13177 is a prime.

It is a super-2 number, since 2×131812 = 347477522, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a plaindrome in base 13 and base 16.

It is a nialpdrome in base 7 and base 12.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 13181.

It is not an unprimeable number, because it can be changed into a prime (13183) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 86 + ... + 183.

It is an arithmetic number, because the mean of its divisors is an integer number (2565).

213181 is an apocalyptic number.

It is an amenable number.

13181 is a deficient number, since it is larger than the sum of its proper divisors (2209).

13181 is an equidigital number, since it uses as much as digits as its factorization.

13181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283 (or 276 counting only the distinct ones).

The product of its digits is 24, while the sum is 14.

The square root of 13181 is about 114.8085362680. The cubic root of 13181 is about 23.6219703477.

Subtracting 13181 from its reverse (18131), we obtain a triangular number (4950 = T99).

It can be divided in two parts, 131 and 81, that added together give a palindrome (212).

The spelling of 13181 in words is "thirteen thousand, one hundred eighty-one".

Divisors: 1 7 49 269 1883 13181