1211021112209 has 4 divisors (see below), whose sum is σ = 1221738113316. Its totient is φ = 1200304111104.

The previous prime is 1211021112163. The next prime is 1211021112229. The reversal of 1211021112209 is 9022111201121.

It is a happy number.

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 370755556609 + 840265555600 = 608897^2 + 916660^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211021112209 - 2²⁸ = 1210752676753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211021112229) 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, 5358500384 + ... + 5358500609.

It is an arithmetic number, because the mean of its divisors is an integer number (305434528329).

Almost surely, 2^{1211021112209} is an apocalyptic number.

It is an amenable number.

1211021112209 is a deficient number, since it is larger than the sum of its proper divisors (10717001107).

1211021112209 is a wasteful number, since it uses less digits than its factorization.

1211021112209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10717001106.

The product of its (nonzero) digits is 144, while the sum is 23.

The spelling of 1211021112209 in words is "one trillion, two hundred eleven billion, twenty-one million, one hundred twelve thousand, two hundred nine".