1221000111221 has 8 divisors (see below), whose sum is σ = 1332009273600. Its totient is φ = 1109992474240.

The previous prime is 1221000111131. The next prime is 1221000111229. The reversal of 1221000111221 is 1221110001221.

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 1221000111221 - 2³⁰ = 1219926369397 is a prime.

It is a super-2 number, since 2×1221000111221² (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 = 1221000111196 and 1221000111205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221000111229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1870460 + ... + 2437338.

It is an arithmetic number, because the mean of its divisors is an integer number (166501159200).

Almost surely, 2^{1221000111221} is an apocalyptic number.

1221000111221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221000111221 is a deficient number, since it is larger than the sum of its proper divisors (111009162379).

1221000111221 is a wasteful number, since it uses less digits than its factorization.

1221000111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 762699.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1221000111221 its reverse (1221110001221), we get a palindrome (2442110112442).

The spelling of 1221000111221 in words is "one trillion, two hundred twenty-one billion, one hundred eleven thousand, two hundred twenty-one".