121211222121 has 20 divisors (see below), whose sum is σ = 197529400464. Its totient is φ = 73461346200.

The previous prime is 121211222101. The next prime is 121211222161. The reversal of 121211222121 is 121222112121.

It is not a de Polignac number, because 121211222121 - 2²¹ = 121209124969 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 121211222094 and 121211222103.

It is not an unprimeable number, because it can be changed into a prime (121211222101) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 68018875 + ... + 68020656.

Almost surely, 2^121211222121 is an apocalyptic number.

121211222121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121211222121 is a deficient number, since it is larger than the sum of its proper divisors (76318178343).

121211222121 is a wasteful number, since it uses less digits than its factorization.

121211222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136039554 (or 136039545 counting only the distinct ones).

The product of its digits is 64, while the sum is 18.

Adding to 121211222121 its reverse (121222112121), we get a palindrome (242433334242).

Subtracting 121211222121 from its reverse (121222112121), we obtain a square (10890000 = 3300²).

The spelling of 121211222121 in words is "one hundred twenty-one billion, two hundred eleven million, two hundred twenty-two thousand, one hundred twenty-one".