121212101 has 4 divisors (see below), whose sum is σ = 121283232. Its totient is φ = 121140972.

The previous prime is 121212097. The next prime is 121212103. The reversal of 121212101 is 101212121.

121212101 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, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 101212121 = 23 ⋅4400527.

It is a cyclic number.

It is not a de Polignac number, because 121212101 - 2² = 121212097 is a prime.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121212103) 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, 32945 + ... + 36438.

It is an arithmetic number, because the mean of its divisors is an integer number (30320808).

Almost surely, 2^121212101 is an apocalyptic number.

It is an amenable number.

121212101 is a deficient number, since it is larger than the sum of its proper divisors (71131).

121212101 is an equidigital number, since it uses as much as digits as its factorization.

121212101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71130.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 121212101 is about 11009.6367333350. The cubic root of 121212101 is about 494.8975756519.

Adding to 121212101 its reverse (101212121), we get a palindrome (222424222).

The spelling of 121212101 in words is "one hundred twenty-one million, two hundred twelve thousand, one hundred one".