1221102221 has 16 divisors (see below), whose sum is σ = 1273478976. Its totient is φ = 1170000000.

The previous prime is 1221102193. The next prime is 1221102229. The reversal of 1221102221 is 1222011221.

It is a cyclic number.

It is not a de Polignac number, because 1221102221 - 2¹⁴ = 1221085837 is a prime.

It is a super-2 number, since 2×1221102221² = 2982181268262265682, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221102196 and 1221102205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221102229) 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, 541346 + ... + 543596.

It is an arithmetic number, because the mean of its divisors is an integer number (79592436).

Almost surely, 2^1221102221 is an apocalyptic number.

It is an amenable number.

1221102221 is a deficient number, since it is larger than the sum of its proper divisors (52376755).

1221102221 is a wasteful number, since it uses less digits than its factorization.

1221102221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2524.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 1221102221 is about 34944.2730787178. The cubic root of 1221102221 is about 1068.8514245206.

Adding to 1221102221 its reverse (1222011221), we get a palindrome (2443113442).

The spelling of 1221102221 in words is "one billion, two hundred twenty-one million, one hundred two thousand, two hundred twenty-one".