1221220011020 has 24 divisors (see below), whose sum is σ = 2564900986704. Its totient is φ = 488423439936.

The previous prime is 1221220011019. The next prime is 1221220011049. The reversal of 1221220011020 is 201100221221.

It is a junction number, because it is equal to n+sod(n) for n = 1221220010986 and 1221220011004.

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, 3880034 + ... + 4182953.

It is an arithmetic number, because the mean of its divisors is an integer number (106870874446).

Almost surely, 2^{1221220011020} is an apocalyptic number.

1221220011020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221220011020 is an abundant number, since it is smaller than the sum of its proper divisors (1343680975684).

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

1221220011020 is a wasteful number, since it uses less digits than its factorization.

1221220011020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8070569 (or 8070567 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 1221220011020 its reverse (201100221221), we get a palindrome (1422320232241).

The spelling of 1221220011020 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, eleven thousand, twenty".