1212201211221 has 72 divisors (see below), whose sum is σ = 2392916801184. Its totient is φ = 581275275840.

The previous prime is 1212201211181. The next prime is 1212201211223. The reversal of 1212201211221 is 1221121022121.

1212201211221 is a `hidden beast` number, since 1 + 212 + 20 + 1 + 211 + 221 = 666.

It is not a de Polignac number, because 1212201211221 - 2¹³ = 1212201203029 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1212201211194 and 1212201211203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212201211223) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 9547971 + ... + 9674096.

It is an arithmetic number, because the mean of its divisors is an integer number (33234955572).

Almost surely, 2^{1212201211221} is an apocalyptic number.

1212201211221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1212201211221 is a deficient number, since it is larger than the sum of its proper divisors (1180715589963).

1212201211221 is a wasteful number, since it uses less digits than its factorization.

1212201211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19222111 (or 19222101 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 1212201211221 its reverse (1221121022121), we get a palindrome (2433322233342).

The spelling of 1212201211221 in words is "one trillion, two hundred twelve billion, two hundred one million, two hundred eleven thousand, two hundred twenty-one".