1221020011021 has 16 divisors (see below), whose sum is σ = 1266380881920. Its totient is φ = 1176037939440.

The previous prime is 1221020011009. The next prime is 1221020011091. The reversal of 1221020011021 is 1201100201221.

It is a cyclic number.

It is not a de Polignac number, because 1221020011021 - 2¹¹ = 1221020008973 is a prime.

It is a super-2 number, since 2×1221020011021² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221020010992 and 1221020011010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221020011091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13639810 + ... + 13729036.

It is an arithmetic number, because the mean of its divisors is an integer number (79148805120).

Almost surely, 2^{1221020011021} is an apocalyptic number.

It is an amenable number.

1221020011021 is a deficient number, since it is larger than the sum of its proper divisors (45360870899).

1221020011021 is a wasteful number, since it uses less digits than its factorization.

1221020011021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91344.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 1221020011021 its reverse (1201100201221), we get a palindrome (2422120212242).

The spelling of 1221020011021 in words is "one trillion, two hundred twenty-one billion, twenty million, eleven thousand, twenty-one".