12121213 has 8 divisors (see below), whose sum is σ = 13122648. Its totient is φ = 11129664.

The previous prime is 12121211. The next prime is 12121231. The reversal of 12121213 is 31212121.

It can be written as a sum of positive squares in 4 ways, for example, as 1375929 + 10745284 = 1173^2 + 3278^2 .

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

It is not a de Polignac number, because 12121213 - 2¹ = 12121211 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12121193 and 12121202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 195 + ... + 4927.

It is an arithmetic number, because the mean of its divisors is an integer number (1640331).

Almost surely, 2^12121213 is an apocalyptic number.

12121213 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

12121213 is a deficient number, since it is larger than the sum of its proper divisors (1001435).

12121213 is a wasteful number, since it uses less digits than its factorization.

12121213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4943.

The product of its digits is 24, while the sum is 13.

The square root of 12121213 is about 3481.5532453203. The cubic root of 12121213 is about 229.7111244122.

Adding to 12121213 its reverse (31212121), we get a palindrome (43333334).

It can be divided in two parts, 1212121 and 3, that multiplied together give a palindrome (3636363).

The spelling of 12121213 in words is "twelve million, one hundred twenty-one thousand, two hundred thirteen".