1210220220221 has 4 divisors (see below), whose sum is σ = 1210999500732. Its totient is φ = 1209440939712.

The previous prime is 1210220220217. The next prime is 1210220220239. The reversal of 1210220220221 is 1220220220121.

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 343671475225 + 866548744996 = 586235^2 + 930886^2 .

It is a cyclic number.

It is not a de Polignac number, because 1210220220221 - 2² = 1210220220217 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1210220220221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1210220220821) 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, 389637926 + ... + 389641031.

It is an arithmetic number, because the mean of its divisors is an integer number (302749875183).

Almost surely, 2^{1210220220221} is an apocalyptic number.

It is an amenable number.

1210220220221 is a deficient number, since it is larger than the sum of its proper divisors (779280511).

1210220220221 is an equidigital number, since it uses as much as digits as its factorization.

1210220220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 779280510.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 1210220220221 its reverse (1220220220121), we get a palindrome (2430440440342).

The spelling of 1210220220221 in words is "one trillion, two hundred ten billion, two hundred twenty million, two hundred twenty thousand, two hundred twenty-one".