1211112212121 has 24 divisors (see below), whose sum is σ = 2019091374144. Its totient is φ = 685211997600.

The previous prime is 1211112212113. The next prime is 1211112212153. The reversal of 1211112212121 is 1212122111121.

It is a happy number.

1211112212121 is a `hidden beast` number, since 121 + 111 + 221 + 212 + 1 = 666.

It is not a de Polignac number, because 1211112212121 - 2³ = 1211112212113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1211112212094 and 1211112212103.

It is not an unprimeable number, because it can be changed into a prime (1211112212021) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 95161971 + ... + 95174696.

It is an arithmetic number, because the mean of its divisors is an integer number (84128807256).

Almost surely, 2^{1211112212121} is an apocalyptic number.

It is an amenable number.

1211112212121 is a deficient number, since it is larger than the sum of its proper divisors (807979162023).

1211112212121 is a wasteful number, since it uses less digits than its factorization.

1211112212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190336781 (or 190336778 counting only the distinct ones).

The product of its digits is 32, while the sum is 18.

Adding to 1211112212121 its reverse (1212122111121), we get a palindrome (2423234323242).

The spelling of 1211112212121 in words is "one trillion, two hundred eleven billion, one hundred twelve million, two hundred twelve thousand, one hundred twenty-one".