1221220011021 has 4 divisors (see below), whose sum is σ = 1628293348032. Its totient is φ = 814146674012.

The previous prime is 1221220011019. The next prime is 1221220011049. The reversal of 1221220011021 is 1201100221221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1221220011021 - 2¹ = 1221220011019 is a prime.

It is a super-2 number, since 2×1221220011021² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221220011071) 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 3 ways as a sum of consecutive naturals, for example, 203536668501 + ... + 203536668506.

It is an arithmetic number, because the mean of its divisors is an integer number (407073337008).

Almost surely, 2^{1221220011021} is an apocalyptic number.

It is an amenable number.

1221220011021 is a deficient number, since it is larger than the sum of its proper divisors (407073337011).

1221220011021 is an equidigital number, since it uses as much as digits as its factorization.

1221220011021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407073337010.

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

Adding to 1221220011021 its reverse (1201100221221), we get a palindrome (2422320232242).

The spelling of 1221220011021 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, eleven thousand, twenty-one".