1211221202121 has 64 divisors (see below), whose sum is σ = 2151340646400. Its totient is φ = 658847649600.

The previous prime is 1211221202101. The next prime is 1211221202143. The reversal of 1211221202121 is 1212021221121.

1211221202121 is a `hidden beast` number, since 1 + 211 + 221 + 20 + 212 + 1 = 666.

It is not a de Polignac number, because 1211221202121 - 2⁵ = 1211221202089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1211221202094 and 1211221202103.

It is not an unprimeable number, because it can be changed into a prime (1211221202101) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1167085 + ... + 1945386.

It is an arithmetic number, because the mean of its divisors is an integer number (33614697600).

Almost surely, 2^{1211221202121} is an apocalyptic number.

It is an amenable number.

1211221202121 is a deficient number, since it is larger than the sum of its proper divisors (940119444279).

1211221202121 is a wasteful number, since it uses less digits than its factorization.

1211221202121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3112587 (or 3112581 counting only the distinct ones).

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

Adding to 1211221202121 its reverse (1212021221121), we get a palindrome (2423242423242).

The spelling of 1211221202121 in words is "one trillion, two hundred eleven billion, two hundred twenty-one million, two hundred two thousand, one hundred twenty-one".