1211522121 has 24 divisors (see below), whose sum is σ = 1763795904. Its totient is φ = 801329760.

The previous prime is 1211522087. The next prime is 1211522173. The reversal of 1211522121 is 1212251121.

1211522121 is a `hidden beast` number, since 1 + 21 + 1 + 522 + 121 = 666.

It is not a de Polignac number, because 1211522121 - 2¹⁰ = 1211521097 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1211522094 and 1211522103.

It is not an unprimeable number, because it can be changed into a prime (1211522021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 753100 + ... + 754706.

It is an arithmetic number, because the mean of its divisors is an integer number (73491496).

Almost surely, 2^1211522121 is an apocalyptic number.

It is an amenable number.

1211522121 is a deficient number, since it is larger than the sum of its proper divisors (552273783).

1211522121 is a wasteful number, since it uses less digits than its factorization.

1211522121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2221 (or 2218 counting only the distinct ones).

The product of its digits is 80, while the sum is 18.

The square root of 1211522121 is about 34806.9263365785. The cubic root of 1211522121 is about 1066.0488747542.

Adding to 1211522121 its reverse (1212251121), we get a palindrome (2423773242).

Subtracting 1211522121 from its reverse (1212251121), we obtain a cube (729000 = 90³).

The spelling of 1211522121 in words is "one billion, two hundred eleven million, five hundred twenty-two thousand, one hundred twenty-one".