1221000220201 has 4 divisors (see below), whose sum is σ = 1263103676100. Its totient is φ = 1178896764304.

The previous prime is 1221000220169. The next prime is 1221000220207. The reversal of 1221000220201 is 1020220001221.

It is a happy number.

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 275914876176 + 945085344025 = 525276^2 + 972155^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221000220201 - 2⁵ = 1221000220169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221000220207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21051727906 + ... + 21051727963.

It is an arithmetic number, because the mean of its divisors is an integer number (315775919025).

Almost surely, 2^{1221000220201} is an apocalyptic number.

It is an amenable number.

1221000220201 is a deficient number, since it is larger than the sum of its proper divisors (42103455899).

1221000220201 is an equidigital number, since it uses as much as digits as its factorization.

1221000220201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42103455898.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 1221000220201 its reverse (1020220001221), we get a palindrome (2241220221422).

The spelling of 1221000220201 in words is "one trillion, two hundred twenty-one billion, two hundred twenty thousand, two hundred one".