1211330121 has 48 divisors (see below), whose sum is σ = 1820387520. Its totient is φ = 713743360.

The previous prime is 1211330089. The next prime is 1211330129. The reversal of 1211330121 is 1210331121.

It is a happy number.

It is not a de Polignac number, because 1211330121 - 2⁵ = 1211330089 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1211330121.

It is not an unprimeable number, because it can be changed into a prime (1211330129) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1591381 + ... + 1592141.

It is an arithmetic number, because the mean of its divisors is an integer number (37924740).

Almost surely, 2^1211330121 is an apocalyptic number.

It is an amenable number.

1211330121 is a deficient number, since it is larger than the sum of its proper divisors (609057399).

1211330121 is a wasteful number, since it uses less digits than its factorization.

1211330121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 886 (or 863 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 1211330121 is about 34804.1681555529. The cubic root of 1211330121 is about 1065.9925565647.

Adding to 1211330121 its reverse (1210331121), we get a palindrome (2421661242).

The spelling of 1211330121 in words is "one billion, two hundred eleven million, three hundred thirty thousand, one hundred twenty-one".