1220021221221 has 24 divisors (see below), whose sum is σ = 1922629887360. Its totient is φ = 739340568000.

The previous prime is 1220021221169. The next prime is 1220021221283. The reversal of 1220021221221 is 1221221200221.

It is a happy number.

1220021221221 is a `hidden beast` number, since 1 + 2 + 200 + 21 + 221 + 221 = 666.

It is not a de Polignac number, because 1220021221221 - 2²¹ = 1220019124069 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1220021221194 and 1220021221203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220021221121) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 570321 + ... + 1662921.

It is an arithmetic number, because the mean of its divisors is an integer number (80109578640).

Almost surely, 2^{1220021221221} is an apocalyptic number.

1220021221221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1220021221221 is a deficient number, since it is larger than the sum of its proper divisors (702608666139).

1220021221221 is a wasteful number, since it uses less digits than its factorization.

1220021221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1103897 (or 1103894 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 1220021221221 its reverse (1221221200221), we get a palindrome (2441242421442).

The spelling of 1220021221221 in words is "one trillion, two hundred twenty billion, twenty-one million, two hundred twenty-one thousand, two hundred twenty-one".