1201212121221 has 64 divisors (see below), whose sum is σ = 2045533593600. Its totient is φ = 682455388608.

The previous prime is 1201212121199. The next prime is 1201212121237. The reversal of 1201212121221 is 1221212121021.

It is not a de Polignac number, because 1201212121221 - 2⁵ = 1201212121189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1201212121194 and 1201212121203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1201212121721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 29024275 + ... + 29065631.

It is an arithmetic number, because the mean of its divisors is an integer number (31961462400).

Almost surely, 2^{1201212121221} is an apocalyptic number.

It is an amenable number.

1201212121221 is a deficient number, since it is larger than the sum of its proper divisors (844321472379).

1201212121221 is a wasteful number, since it uses less digits than its factorization.

1201212121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42255 (or 42249 counting only the distinct ones).

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

Adding to 1201212121221 its reverse (1221212121021), we get a palindrome (2422424242242).

The spelling of 1201212121221 in words is "one trillion, two hundred one billion, two hundred twelve million, one hundred twenty-one thousand, two hundred twenty-one".