1221132221 has 8 divisors (see below), whose sum is σ = 1243709088. Its totient is φ = 1198638000.

The previous prime is 1221132193. The next prime is 1221132251. The reversal of 1221132221 is 1222311221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221132221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221132221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221132251) 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, 9566 + ... + 50336.

It is an arithmetic number, because the mean of its divisors is an integer number (155463636).

Almost surely, 2^1221132221 is an apocalyptic number.

It is an amenable number.

1221132221 is a deficient number, since it is larger than the sum of its proper divisors (22576867).

1221132221 is an equidigital number, since it uses as much as digits as its factorization.

1221132221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41323.

The product of its digits is 96, while the sum is 17.

The square root of 1221132221 is about 34944.7023309686. The cubic root of 1221132221 is about 1068.8601776180.

Adding to 1221132221 its reverse (1222311221), we get a palindrome (2443443442).

The spelling of 1221132221 in words is "one billion, two hundred twenty-one million, one hundred thirty-two thousand, two hundred twenty-one".