1221221101021 has 8 divisors (see below), whose sum is σ = 1263925072800. Its totient is φ = 1178556655920.

The previous prime is 1221221100977. The next prime is 1221221101039. The reversal of 1221221101021 is 1201011221221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221221101021 - 2⁹ = 1221221100509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221221100986 and 1221221101004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221221101621) 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, 9818791 + ... + 9942388.

It is an arithmetic number, because the mean of its divisors is an integer number (157990634100).

Almost surely, 2^{1221221101021} is an apocalyptic number.

It is an amenable number.

1221221101021 is a deficient number, since it is larger than the sum of its proper divisors (42703971779).

1221221101021 is a wasteful number, since it uses less digits than its factorization.

1221221101021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19763339.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 1221221101021 its reverse (1201011221221), we get a palindrome (2422232322242).

The spelling of 1221221101021 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, one hundred one thousand, twenty-one".