12101212121 has 4 divisors (see below), whose sum is σ = 12329536932. Its totient is φ = 11872887312.

The previous prime is 12101212099. The next prime is 12101212129. The reversal of 12101212121 is 12121210121.

12101212121 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

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

It can be written as a sum of positive squares in 2 ways, for example, as 3602400400 + 8498811721 = 60020^2 + 92189^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12101212121 is a prime.

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

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12101212096 and 12101212105.

It is not an unprimeable number, because it can be changed into a prime (12101212129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114162326 + ... + 114162431.

It is an arithmetic number, because the mean of its divisors is an integer number (3082384233).

Almost surely, 2^12101212121 is an apocalyptic number.

It is an amenable number.

12101212121 is a deficient number, since it is larger than the sum of its proper divisors (228324811).

12101212121 is an equidigital number, since it uses as much as digits as its factorization.

12101212121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228324810.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 12101212121 its reverse (12121210121), we get a palindrome (24222422242).

The spelling of 12101212121 in words is "twelve billion, one hundred one million, two hundred twelve thousand, one hundred twenty-one".