1211221020021 has 8 divisors (see below), whose sum is σ = 1615165326720. Its totient is φ = 807378696672.

The previous prime is 1211221020007. The next prime is 1211221020071. The reversal of 1211221020021 is 1200201221121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1211221020021 - 2⁵ = 1211221019989 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211221020071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25468120 + ... + 25515633.

It is an arithmetic number, because the mean of its divisors is an integer number (201895665840).

Almost surely, 2^{1211221020021} is an apocalyptic number.

It is an amenable number.

1211221020021 is a deficient number, since it is larger than the sum of its proper divisors (403944306699).

1211221020021 is an equidigital number, since it uses as much as digits as its factorization.

1211221020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50991675.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1211221020021 its reverse (1200201221121), we get a palindrome (2411422241142).

The spelling of 1211221020021 in words is "one trillion, two hundred eleven billion, two hundred twenty-one million, twenty thousand, twenty-one".