121212 has 72 divisors (see below), whose sum is σ = 387296. Its totient is φ = 31104.

The previous prime is 121189. The next prime is 121229. The reversal of 121212 is 212121.

121212 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a nude number because it is divisible by every one of its digits.

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

121212 is an undulating number in base 10.

121212 is a modest number, since divided by 1212 gives 12 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 121194 and 121203.

It is a congruent number.

It is an unprimeable 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 23 ways as a sum of consecutive naturals, for example, 3258 + ... + 3294.

2¹²¹²¹² is an apocalyptic number.

121212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (193648).

121212 is an abundant number, since it is smaller than the sum of its proper divisors (266084).

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

121212 is a wasteful number, since it uses less digits than its factorization.

121212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67 (or 62 counting only the distinct ones).

The product of its digits is 8, while the sum is 9.

The square root of 121212 is about 348.1551378337. The cubic root of 121212 is about 49.4897438194.

Adding to 121212 its reverse (212121), we get a palindrome (333333).

Subtracting 121212 from its reverse (212121), we obtain a palindrome (90909).

It can be divided in two parts, 12121 and 2, that multiplied together give a palindrome (24242).

The spelling of 121212 in words is "one hundred twenty-one thousand, two hundred twelve", and thus it is an iban number.