61181 has 4 divisors (see below), whose sum is σ = 61692. Its totient is φ = 60672.

The previous prime is 61169. The next prime is 61211. The reversal of 61181 is 18116.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 8281 + 52900 = 91^2 + 230^2 .

It is a cyclic number.

It is not a de Polignac number, because 61181 - 2¹⁴ = 44797 is a prime.

It is a super-2 number, since 2×61181² = 7486229522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35 + ... + 351.

It is an arithmetic number, because the mean of its divisors is an integer number (15423).

2⁶¹¹⁸¹ is an apocalyptic number.

It is an amenable number.

61181 is a deficient number, since it is larger than the sum of its proper divisors (511).

61181 is a wasteful number, since it uses less digits than its factorization.

61181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 510.

The product of its digits is 48, while the sum is 17.

The square root of 61181 is about 247.3479330821. The cubic root of 61181 is about 39.4038681387.

Adding to 61181 its reverse (18116), we get a palindrome (79297).

It can be divided in two parts, 61 and 181, that added together give a palindrome (242).

The spelling of 61181 in words is "sixty-one thousand, one hundred eighty-one".