1201221221 has 4 divisors (see below), whose sum is σ = 1201610700. Its totient is φ = 1200831744.

The previous prime is 1201221143. The next prime is 1201221223. The reversal of 1201221221 is 1221221021.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1221221021 = 641 ⋅1905181.

It can be written as a sum of positive squares in 2 ways, for example, as 129640996 + 1071580225 = 11386^2 + 32735^2 .

It is a cyclic number.

It is not a de Polignac number, because 1201221221 - 2¹⁰ = 1201220197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1201221196 and 1201221205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1201221223) 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, 190076 + ... + 196293.

It is an arithmetic number, because the mean of its divisors is an integer number (300402675).

Almost surely, 2^1201221221 is an apocalyptic number.

It is an amenable number.

1201221221 is a deficient number, since it is larger than the sum of its proper divisors (389479).

1201221221 is an equidigital number, since it uses as much as digits as its factorization.

1201221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389478.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 1201221221 is about 34658.6384758548. The cubic root of 1201221221 is about 1063.0189305657.

Adding to 1201221221 its reverse (1221221021), we get a palindrome (2422442242).

It can be divided in two parts, 12012 and 21221, that added together give a palindrome (33233).

The spelling of 1201221221 in words is "one billion, two hundred one million, two hundred twenty-one thousand, two hundred twenty-one".