1212220120221 has 72 divisors (see below), whose sum is σ = 2048699016000. Its totient is φ = 688190152320.

The previous prime is 1212220120219. The next prime is 1212220120271. The reversal of 1212220120221 is 1220210222121.

It is a happy number.

1212220120221 is a `hidden beast` number, since 1 + 212 + 220 + 12 + 0 + 221 = 666.

It is not a de Polignac number, because 1212220120221 - 2¹ = 1212220120219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1212220120194 and 1212220120203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212220120211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1512360 + ... + 2170638.

It is an arithmetic number, because the mean of its divisors is an integer number (28454153000).

Almost surely, 2^{1212220120221} is an apocalyptic number.

1212220120221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1212220120221 is a deficient number, since it is larger than the sum of its proper divisors (836478895779).

1212220120221 is a wasteful number, since it uses less digits than its factorization.

1212220120221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 658415 (or 658401 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 1212220120221 its reverse (1220210222121), we get a palindrome (2432430342342).

The spelling of 1212220120221 in words is "one trillion, two hundred twelve billion, two hundred twenty million, one hundred twenty thousand, two hundred twenty-one".