1221212201020 has 72 divisors (see below), whose sum is σ = 3003003914400. Its totient is φ = 415928419200.

The previous prime is 1221212200997. The next prime is 1221212201021. The reversal of 1221212201020 is 201022121221.

It is a happy number.

It is a super-2 number, since 2×1221212201020² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221212200985 and 1221212201003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221212201021) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3978295 + ... + 4274254.

It is an arithmetic number, because the mean of its divisors is an integer number (41708387700).

Almost surely, 2^{1221212201020} is an apocalyptic number.

1221212201020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221212201020 is an abundant number, since it is smaller than the sum of its proper divisors (1781791713380).

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

1221212201020 is a wasteful number, since it uses less digits than its factorization.

1221212201020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8252723 (or 8252714 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 1221212201020 its reverse (201022121221), we get a palindrome (1422234322241).

The spelling of 1221212201020 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, two hundred one thousand, twenty".