1210801221 has 18 divisors (see below), whose sum is σ = 2034476262. Its totient is φ = 691886160.

The previous prime is 1210801219. The next prime is 1210801237. The reversal of 1210801221 is 1221080121.

It can be written as a sum of positive squares in only one way, i.e., 1177450596 + 33350625 = 34314^2 + 5775^2 .

It is not a de Polignac number, because 1210801221 - 2¹ = 1210801219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1210801194 and 1210801203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1210801211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1372350 + ... + 1373231.

It is an arithmetic number, because the mean of its divisors is an integer number (113026459).

Almost surely, 2^1210801221 is an apocalyptic number.

It is an amenable number.

1210801221 is a deficient number, since it is larger than the sum of its proper divisors (823675041).

1210801221 is a wasteful number, since it uses less digits than its factorization.

1210801221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2745601 (or 2745591 counting only the distinct ones).

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

The square root of 1210801221 is about 34796.5690981166. The cubic root of 1210801221 is about 1065.8373867695.

Adding to 1210801221 its reverse (1221080121), we get a palindrome (2431881342).

The spelling of 1210801221 in words is "one billion, two hundred ten million, eight hundred one thousand, two hundred twenty-one".