1211102221 has 4 divisors (see below), whose sum is σ = 1384116832. Its totient is φ = 1038087612.

The previous prime is 1211102183. The next prime is 1211102257. The reversal of 1211102221 is 1222011121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1222011121 = 15473 ⋅78977.

It is a cyclic number.

It is not a de Polignac number, because 1211102221 - 2¹¹ = 1211100173 is a prime.

It is a super-2 number, since 2×1211102221² = 2933537179422265682, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211102821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86507295 + ... + 86507308.

It is an arithmetic number, because the mean of its divisors is an integer number (346029208).

Almost surely, 2^1211102221 is an apocalyptic number.

It is an amenable number.

1211102221 is a deficient number, since it is larger than the sum of its proper divisors (173014611).

1211102221 is an equidigital number, since it uses as much as digits as its factorization.

1211102221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173014610.

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

The square root of 1211102221 is about 34800.8939684026. The cubic root of 1211102221 is about 1065.9257003222.

Adding to 1211102221 its reverse (1222011121), we get a palindrome (2433113342).

The spelling of 1211102221 in words is "one billion, two hundred eleven million, one hundred two thousand, two hundred twenty-one".