1221220220020 has 24 divisors (see below), whose sum is σ = 2565101548800. Its totient is φ = 488385404832.

The previous prime is 1221220219987. The next prime is 1221220220053. The reversal of 1221220220020 is 200220221221.

It is an interprime number because it is at equal distance from previous prime (1221220219987) and next prime (1221220220053).

It is a junction number, because it is equal to n+sod(n) for n = 1221220219976 and 1221220220003.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6320140 + ... + 6510499.

It is an arithmetic number, because the mean of its divisors is an integer number (106879231200).

Almost surely, 2^{1221220220020} is an apocalyptic number.

1221220220020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221220220020 is an abundant number, since it is smaller than the sum of its proper divisors (1343881328780).

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

1221220220020 is a wasteful number, since it uses less digits than its factorization.

1221220220020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12835407 (or 12835405 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 1221220220020 its reverse (200220221221), we get a palindrome (1421440441241).

The spelling of 1221220220020 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, two hundred twenty thousand, twenty".