12121212105 has 24 divisors (see below), whose sum is σ = 21175544832. Its totient is φ = 6413740704.

The previous prime is 12121212067. The next prime is 12121212121. The reversal of 12121212105 is 50121212121.

It is not a de Polignac number, because 12121212105 - 2¹² = 12121208009 is a prime.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1054759 + ... + 1066188.

It is an arithmetic number, because the mean of its divisors is an integer number (882314368).

Almost surely, 2^12121212105 is an apocalyptic number.

12121212105 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12121212105 is a deficient number, since it is larger than the sum of its proper divisors (9054332727).

12121212105 is a wasteful number, since it uses less digits than its factorization.

12121212105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2121085 (or 2121082 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 18.

Adding to 12121212105 its reverse (50121212121), we get a palindrome (62242424226).

The spelling of 12121212105 in words is "twelve billion, one hundred twenty-one million, two hundred twelve thousand, one hundred five".