12121878 has 8 divisors (see below), whose sum is σ = 24243768. Its totient is φ = 4040624.

The previous prime is 12121873. The next prime is 12121883. The reversal of 12121878 is 87812121.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (12121873) and next prime (12121883).

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

12121878 is an admirable number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121871) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1010151 + ... + 1010162.

It is an arithmetic number, because the mean of its divisors is an integer number (3030471).

Almost surely, 2^12121878 is an apocalyptic number.

12121878 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

12121878 is a wasteful number, since it uses less digits than its factorization.

12121878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2020318.

The product of its digits is 1792, while the sum is 30.

The square root of 12121878 is about 3481.6487473609. The cubic root of 12121878 is about 229.7153251773.

Adding to 12121878 its reverse (87812121), we get a palindrome (99933999).

The spelling of 12121878 in words is "twelve million, one hundred twenty-one thousand, eight hundred seventy-eight".