1221000111021 has 8 divisors (see below), whose sum is σ = 1642407229440. Its totient is φ = 806796533312.

The previous prime is 1221000111011. The next prime is 1221000111053. The reversal of 1221000111021 is 1201110001221.

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 1221000111021 - 2¹⁸ = 1220999848877 is a prime.

It is a super-2 number, since 2×1221000111021² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221000110988 and 1221000111006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221000111011) 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 7 ways as a sum of consecutive naturals, for example, 1800884781 + ... + 1800885458.

It is an arithmetic number, because the mean of its divisors is an integer number (205300903680).

Almost surely, 2^{1221000111021} is an apocalyptic number.

It is an amenable number.

1221000111021 is a deficient number, since it is larger than the sum of its proper divisors (421407118419).

1221000111021 is a wasteful number, since it uses less digits than its factorization.

1221000111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3601770355.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 1221000111021 its reverse (1201110001221), we get a palindrome (2422110112242).

The spelling of 1221000111021 in words is "one trillion, two hundred twenty-one billion, one hundred eleven thousand, twenty-one".