1221021333020 has 24 divisors (see below), whose sum is σ = 2564170247184. Its totient is φ = 488403686016.

The previous prime is 1221021333019. The next prime is 1221021333031. The reversal of 1221021333020 is 203331201221.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 1221021332983 and 1221021333001.

It is a congruent number.

It is an unprimeable number.

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, 2314019 + ... + 2792261.

It is an arithmetic number, because the mean of its divisors is an integer number (106840426966).

Almost surely, 2^{1221021333020} is an apocalyptic number.

1221021333020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221021333020 is an abundant number, since it is smaller than the sum of its proper divisors (1343148914164).

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

1221021333020 is a wasteful number, since it uses less digits than its factorization.

1221021333020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 605909 (or 605907 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 1221021333020 its reverse (203331201221), we get a palindrome (1424352534241).

The spelling of 1221021333020 in words is "one trillion, two hundred twenty-one billion, twenty-one million, three hundred thirty-three thousand, twenty".