1211011222121 has 4 divisors (see below), whose sum is σ = 1211519839044. Its totient is φ = 1210502605200.

The previous prime is 1211011222103. The next prime is 1211011222129. The reversal of 1211011222121 is 1212221101121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2471581225 + 1208539640896 = 49715^2 + 1099336^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211011222121 - 2²² = 1211007027817 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1211011222121.

It is not an unprimeable number, because it can be changed into a prime (1211011222129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 254304890 + ... + 254309651.

It is an arithmetic number, because the mean of its divisors is an integer number (302879959761).

Almost surely, 2^{1211011222121} is an apocalyptic number.

It is an amenable number.

1211011222121 is a deficient number, since it is larger than the sum of its proper divisors (508616923).

1211011222121 is an equidigital number, since it uses as much as digits as its factorization.

1211011222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 508616922.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 1211011222121 its reverse (1212221101121), we get a palindrome (2423232323242).

The spelling of 1211011222121 in words is "one trillion, two hundred eleven billion, eleven million, two hundred twenty-two thousand, one hundred twenty-one".