1221010101020 has 12 divisors (see below), whose sum is σ = 2564121212184. Its totient is φ = 488404040400.

The previous prime is 1221010100987. The next prime is 1221010101029. The reversal of 1221010101020 is 201010101221.

It is a junction number, because it is equal to n+sod(n) for n = 1221010100992 and 1221010101010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221010101029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30525252506 + ... + 30525252545.

It is an arithmetic number, because the mean of its divisors is an integer number (213676767682).

Almost surely, 2^{1221010101020} is an apocalyptic number.

1221010101020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221010101020 is an abundant number, since it is smaller than the sum of its proper divisors (1343111111164).

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

1221010101020 is a wasteful number, since it uses less digits than its factorization.

1221010101020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61050505060 (or 61050505058 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 1221010101020 its reverse (201010101221), we get a palindrome (1422020202241).

The spelling of 1221010101020 in words is "one trillion, two hundred twenty-one billion, ten million, one hundred one thousand, twenty".