1211011320221 has 12 divisors (see below), whose sum is σ = 1286568064992. Its totient is φ = 1139659796928.

The previous prime is 1211011320217. The next prime is 1211011320287. The reversal of 1211011320221 is 1220231101121.

It is a happy number.

It is not a de Polignac number, because 1211011320221 - 2² = 1211011320217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1211011320221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211011320121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2712386 + ... + 3127148.

It is an arithmetic number, because the mean of its divisors is an integer number (107214005416).

Almost surely, 2^{1211011320221} is an apocalyptic number.

It is an amenable number.

1211011320221 is a deficient number, since it is larger than the sum of its proper divisors (75556744771).

1211011320221 is a wasteful number, since it uses less digits than its factorization.

1211011320221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 424900 (or 424883 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 1211011320221 its reverse (1220231101121), we get a palindrome (2431242421342).

The spelling of 1211011320221 in words is "one trillion, two hundred eleven billion, eleven million, three hundred twenty thousand, two hundred twenty-one".