20121212129 has 16 divisors (see below), whose sum is σ = 21515466240. Its totient is φ = 18775344000.

The previous prime is 20121212117. The next prime is 20121212171. The reversal of 20121212129 is 92121212102.

It is a cyclic number.

It is not a de Polignac number, because 20121212129 - 2¹² = 20121208033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20121212329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 669434 + ... + 698844.

It is an arithmetic number, because the mean of its divisors is an integer number (1344716640).

Almost surely, 2^20121212129 is an apocalyptic number.

20121212129 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

20121212129 is a deficient number, since it is larger than the sum of its proper divisors (1394254111).

20121212129 is a wasteful number, since it uses less digits than its factorization.

20121212129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30232.

The product of its (nonzero) digits is 288, while the sum is 23.

The spelling of 20121212129 in words is "twenty billion, one hundred twenty-one million, two hundred twelve thousand, one hundred twenty-nine".