12121988 has 6 divisors (see below), whose sum is σ = 21213486. Its totient is φ = 6060992.

The previous prime is 12121987. The next prime is 12122009. The reversal of 12121988 is 88912121.

It can be written as a sum of positive squares in only one way, i.e., 7828804 + 4293184 = 2798^2 + 2072^2 .

It is not an unprimeable number, because it can be changed into a prime (12121987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1515245 + ... + 1515252.

It is an arithmetic number, because the mean of its divisors is an integer number (3535581).

Almost surely, 2^12121988 is an apocalyptic number.

It is an amenable number.

12121988 is a deficient number, since it is larger than the sum of its proper divisors (9091498).

12121988 is a wasteful number, since it uses less digits than its factorization.

12121988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3030501 (or 3030499 counting only the distinct ones).

The product of its digits is 2304, while the sum is 32.

The square root of 12121988 is about 3481.6645444385. The cubic root of 12121988 is about 229.7160200259.

The spelling of 12121988 in words is "twelve million, one hundred twenty-one thousand, nine hundred eighty-eight".