121986 has 24 divisors (see below), whose sum is σ = 275184. Its totient is φ = 40500.

The previous prime is 121967. The next prime is 121993. The reversal of 121986 is 689121.

121986 is nontrivially palindromic in base 5.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 361 + ... + 611.

It is an arithmetic number, because the mean of its divisors is an integer number (11466).

2¹²¹⁹⁸⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121986, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137592).

121986 is an abundant number, since it is smaller than the sum of its proper divisors (153198).

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

121986 is an equidigital number, since it uses as much as digits as its factorization.

121986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268 (or 256 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 121986 is about 349.2649424148. The cubic root of 121986 is about 49.5948594222.

It can be divided in two parts, 12 and 1986, that multiplied together give a palindrome (23832).

The spelling of 121986 in words is "one hundred twenty-one thousand, nine hundred eighty-six".