11211220121021 has 8 divisors (see below), whose sum is σ = 11226150169080. Its totient is φ = 11196299342592.

The previous prime is 11211220120987. The next prime is 11211220121071. The reversal of 11211220121021 is 12012102211211.

It can be written as a sum of positive squares in 4 ways, for example, as 8708135412025 + 2503084708996 = 2950955^2 + 1582114^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11211220121021 is a prime.

It is a super-2 number, since 2×11211220121021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11211220121071) 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 7 ways as a sum of consecutive naturals, for example, 104801 + ... + 4736393.

It is an arithmetic number, because the mean of its divisors is an integer number (1403268771135).

Almost surely, 2^{11211220121021} is an apocalyptic number.

It is an amenable number.

11211220121021 is a deficient number, since it is larger than the sum of its proper divisors (14930048059).

11211220121021 is a wasteful number, since it uses less digits than its factorization.

11211220121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4634815.

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

Adding to 11211220121021 its reverse (12012102211211), we get a palindrome (23223322332232).

The spelling of 11211220121021 in words is "eleven trillion, two hundred eleven billion, two hundred twenty million, one hundred twenty-one thousand, twenty-one".