1211001021211 has 4 divisors (see below), whose sum is σ = 1211996093112. Its totient is φ = 1210005949312.

The previous prime is 1211001021151. The next prime is 1211001021259. The reversal of 1211001021211 is 1121201001121.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1211001021211 - 2¹⁵ = 1211000988443 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211001021191 and 1211001021200.

It is not an unprimeable number, because it can be changed into a prime (1211001021271) 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, 497534125 + ... + 497536558.

It is an arithmetic number, because the mean of its divisors is an integer number (302999023278).

Almost surely, 2^{1211001021211} is an apocalyptic number.

1211001021211 is a deficient number, since it is larger than the sum of its proper divisors (995071901).

1211001021211 is an equidigital number, since it uses as much as digits as its factorization.

1211001021211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 995071900.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 1211001021211 its reverse (1121201001121), we get a palindrome (2332202022332).

The spelling of 1211001021211 in words is "one trillion, two hundred eleven billion, one million, twenty-one thousand, two hundred eleven".