Adding to 122121101 its reverse (101121221), we get a palindrome (223242322).
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: 101121221 = 59 ⋅1713919.
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-122121101 is a prime.
It is a Duffinian number.
It is a Curzon number.
It is a congruent number.
Almost surely, 2122121101 is an apocalyptic number.
It is an amenable number.
122121101 is an equidigital number, since it uses as much as digits as its factorization.
122121101 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 1822770.
The square root of 122121101 is about 11050.8416421556. The cubic root of 122121101 is about 496.1316164007.
The spelling of 122121101 in words is "one hundred twenty-two million, one hundred twenty-one thousand, one hundred one".