1221110221 has 16 divisors (see below), whose sum is σ = 1407931200. Its totient is φ = 1051239168.

The previous prime is 1221110161. The next prime is 1221110237. The reversal of 1221110221 is 1220111221.

It is a cyclic number.

It is not a de Polignac number, because 1221110221 - 2⁹ = 1221109709 is a prime.

It is a super-2 number, since 2×1221110221² = 2982220343661337682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221110251) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55815 + ... + 74548.

It is an arithmetic number, because the mean of its divisors is an integer number (87995700).

Almost surely, 2^1221110221 is an apocalyptic number.

It is an amenable number.

1221110221 is a deficient number, since it is larger than the sum of its proper divisors (186820979).

1221110221 is a wasteful number, since it uses less digits than its factorization.

1221110221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130428.

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

The square root of 1221110221 is about 34944.3875465002. The cubic root of 1221110221 is about 1068.8537586939.

Adding to 1221110221 its reverse (1220111221), we get a palindrome (2441221442).

The spelling of 1221110221 in words is "one billion, two hundred twenty-one million, one hundred ten thousand, two hundred twenty-one".