1220121221 has 8 divisors (see below), whose sum is σ = 1331313600. Its totient is φ = 1108974240.

The previous prime is 1220121169. The next prime is 1220121247. The reversal of 1220121221 is 1221210221.

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

It is not a de Polignac number, because 1220121221 - 2²² = 1215926917 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220121196 and 1220121205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220121251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70640 + ... + 86198.

It is an arithmetic number, because the mean of its divisors is an integer number (166414200).

Almost surely, 2^1220121221 is an apocalyptic number.

1220121221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1220121221 is a deficient number, since it is larger than the sum of its proper divisors (111192379).

1220121221 is a wasteful number, since it uses less digits than its factorization.

1220121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22699.

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

The square root of 1220121221 is about 34930.2336236104. The cubic root of 1220121221 is about 1068.5651192070.

Adding to 1220121221 its reverse (1221210221), we get a palindrome (2441331442).

The spelling of 1220121221 in words is "one billion, two hundred twenty million, one hundred twenty-one thousand, two hundred twenty-one".