61686181 has 8 divisors (see below), whose sum is σ = 63955584. Its totient is φ = 59453280.

The previous prime is 61686151. The next prime is 61686193. The reversal of 61686181 is 18168616.

It is a happy number.

61686181 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-61686181 is a prime.

It is a super-2 number, since 2×61686181² = 7610369852729522, which contains 22 as substring.

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 61686181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61686101) 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 7 ways as a sum of consecutive naturals, for example, 5661 + ... + 12466.

It is an arithmetic number, because the mean of its divisors is an integer number (7994448).

Almost surely, 2^61686181 is an apocalyptic number.

It is an amenable number.

61686181 is a deficient number, since it is larger than the sum of its proper divisors (2269403).

61686181 is a wasteful number, since it uses less digits than its factorization.

61686181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18251.

The product of its digits is 13824, while the sum is 37.

The square root of 61686181 is about 7854.0550672885. The cubic root of 61686181 is about 395.1202560730.

The spelling of 61686181 in words is "sixty-one million, six hundred eighty-six thousand, one hundred eighty-one".