121812 has 12 divisors (see below), whose sum is σ = 284256. Its totient is φ = 40600.

The previous prime is 121789. The next prime is 121843. The reversal of 121812 is 218121.

It is a tau number, because it is divible by the number of its divisors (12).

It is a Smith number, since the sum of its digits (15) coincides with the sum of the digits of its prime factors.

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 121791 and 121800.

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 121812.

It is an unprimeable number.

121812 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 (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5064 + ... + 5087.

It is an arithmetic number, because the mean of its divisors is an integer number (23688).

2¹²¹⁸¹² is an apocalyptic number.

121812 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

121812 is an abundant number, since it is smaller than the sum of its proper divisors (162444).

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

121812 is a wasteful number, since it uses less digits than its factorization.

121812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10158 (or 10156 counting only the distinct ones).

The product of its digits is 32, while the sum is 15.

The square root of 121812 is about 349.0157589565. The cubic root of 121812 is about 49.5712676116.

Adding to 121812 its reverse (218121), we get a palindrome (339933).

The spelling of 121812 in words is "one hundred twenty-one thousand, eight hundred twelve".