61986 has 8 divisors (see below), whose sum is σ = 123984. Its totient is φ = 20660.

The previous prime is 61981. The next prime is 61987. The reversal of 61986 is 68916.

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

61986 is an admirable number.

It is a Curzon number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (61981) by changing a digit.

61986 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5160 + ... + 5171.

It is an arithmetic number, because the mean of its divisors is an integer number (15498).

2⁶¹⁹⁸⁶ is an apocalyptic number.

61986 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (61992).

61986 is a wasteful number, since it uses less digits than its factorization.

61986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10336.

The product of its digits is 2592, while the sum is 30.

The square root of 61986 is about 248.9698776961. The cubic root of 61986 is about 39.5759368143.

The spelling of 61986 in words is "sixty-one thousand, nine hundred eighty-six".