1221212120201 has 4 divisors (see below), whose sum is σ = 1244253858372. Its totient is φ = 1198170382032.

The previous prime is 1221212120159. The next prime is 1221212120353. The reversal of 1221212120201 is 1020212121221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 664308132601 + 556903987600 = 815051^2 + 746260^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221212120201 - 2⁶ = 1221212120137 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221212120201.

It is not an unprimeable number, because it can be changed into a prime (1221212020201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11520869006 + ... + 11520869111.

It is an arithmetic number, because the mean of its divisors is an integer number (311063464593).

Almost surely, 2^{1221212120201} is an apocalyptic number.

It is an amenable number.

1221212120201 is a deficient number, since it is larger than the sum of its proper divisors (23041738171).

1221212120201 is an equidigital number, since it uses as much as digits as its factorization.

1221212120201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23041738170.

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

Adding to 1221212120201 its reverse (1020212121221), we get a palindrome (2241424241422).

The spelling of 1221212120201 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, one hundred twenty thousand, two hundred one".