1221111222220 has 12 divisors (see below), whose sum is σ = 2564333566704. Its totient is φ = 488444488880.

The previous prime is 1221111222209. The next prime is 1221111222251. The reversal of 1221111222220 is 222221111221.

It is a super-2 number, since 2×1221111222220² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30527780536 + ... + 30527780575.

It is an arithmetic number, because the mean of its divisors is an integer number (213694463892).

Almost surely, 2^{1221111222220} is an apocalyptic number.

1221111222220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221111222220 is an abundant number, since it is smaller than the sum of its proper divisors (1343222344484).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221111222220 is a wasteful number, since it uses less digits than its factorization.

1221111222220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61055561120 (or 61055561118 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 1221111222220 its reverse (222221111221), we get a palindrome (1443332333441).

The spelling of 1221111222220 in words is "one trillion, two hundred twenty-one billion, one hundred eleven million, two hundred twenty-two thousand, two hundred twenty".