1211212120220 has 24 divisors (see below), whose sum is σ = 2631253917600. Its totient is φ = 467778473792.

The previous prime is 1211212120211. The next prime is 1211212120241. The reversal of 1211212120220 is 220212121121.

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, 1044147800 + ... + 1044148959.

It is an arithmetic number, because the mean of its divisors is an integer number (109635579900).

Almost surely, 2^{1211212120220} is an apocalyptic number.

1211212120220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211212120220 is an abundant number, since it is smaller than the sum of its proper divisors (1420041797380).

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

1211212120220 is a wasteful number, since it uses less digits than its factorization.

1211212120220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2088296797 (or 2088296795 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 1211212120220 its reverse (220212121121), we get a palindrome (1431424241341).

Subtracting from 1211212120220 its reverse (220212121121), we obtain a palindrome (990999999099).

The spelling of 1211212120220 in words is "one trillion, two hundred eleven billion, two hundred twelve million, one hundred twenty thousand, two hundred twenty".