1221000222020 has 96 divisors (see below), whose sum is σ = 2766369715200. Its totient is φ = 451166976000.

The previous prime is 1221000222017. The next prime is 1221000222031. The reversal of 1221000222020 is 202220001221.

It is a junction number, because it is equal to n+sod(n) for n = 1221000221986 and 1221000222004.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 30376496 + ... + 30416664.

It is an arithmetic number, because the mean of its divisors is an integer number (28816351200).

Almost surely, 2^{1221000222020} is an apocalyptic number.

1221000222020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221000222020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1383184857600).

1221000222020 is an abundant number, since it is smaller than the sum of its proper divisors (1545369493180).

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

1221000222020 is a wasteful number, since it uses less digits than its factorization.

1221000222020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42189 (or 42187 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 1221000222020 its reverse (202220001221), we get a palindrome (1423220223241).

The spelling of 1221000222020 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-two thousand, twenty".