12121378 has 4 divisors (see below), whose sum is σ = 18182070. Its totient is φ = 6060688.

The previous prime is 12121367. The next prime is 12121379. The reversal of 12121378 is 87312121.

It is a happy number.

12121378 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 11269449 + 851929 = 3357^2 + 923^2 .

It is not an unprimeable number, because it can be changed into a prime (12121379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3030343 + ... + 3030346.

Almost surely, 2^12121378 is an apocalyptic number.

12121378 is a deficient number, since it is larger than the sum of its proper divisors (6060692).

12121378 is an equidigital number, since it uses as much as digits as its factorization.

12121378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6060691.

The product of its digits is 672, while the sum is 25.

The square root of 12121378 is about 3481.5769415597. The cubic root of 12121378 is about 229.7121667217.

Adding to 12121378 its reverse (87312121), we get a palindrome (99433499).

The spelling of 12121378 in words is "twelve million, one hundred twenty-one thousand, three hundred seventy-eight".