1221555222217 has 8 divisors (see below), whose sum is σ = 1345543617600. Its totient is φ = 1099723146960.

The previous prime is 1221555222137. The next prime is 1221555222229. The reversal of 1221555222217 is 7122225551221.

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-1221555222217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221555222247) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 539078842 + ... + 539081107.

It is an arithmetic number, because the mean of its divisors is an integer number (168192952200).

Almost surely, 2^{1221555222217} is an apocalyptic number.

It is an amenable number.

1221555222217 is a deficient number, since it is larger than the sum of its proper divisors (123988395383).

1221555222217 is a wasteful number, since it uses less digits than its factorization.

1221555222217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1078160063.

The product of its digits is 56000, while the sum is 37.

The spelling of 1221555222217 in words is "one trillion, two hundred twenty-one billion, five hundred fifty-five million, two hundred twenty-two thousand, two hundred seventeen".