1211133121 has 16 divisors (see below), whose sum is σ = 1348300800. Its totient is φ = 1078693200.

The previous prime is 1211133109. The next prime is 1211133127. The reversal of 1211133121 is 1213311121.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1211133121 - 2⁵ = 1211133089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1211133095 and 1211133104.

It is not an unprimeable number, because it can be changed into a prime (1211133127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 108520 + ... + 119158.

It is an arithmetic number, because the mean of its divisors is an integer number (84268800).

Almost surely, 2^1211133121 is an apocalyptic number.

1211133121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1211133121 is a deficient number, since it is larger than the sum of its proper divisors (137167679).

1211133121 is a wasteful number, since it uses less digits than its factorization.

1211133121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10860.

The product of its digits is 36, while the sum is 16.

The square root of 1211133121 is about 34801.3379196835. The cubic root of 1211133121 is about 1065.9347655697.

Adding to 1211133121 its reverse (1213311121), we get a palindrome (2424444242).

The spelling of 1211133121 in words is "one billion, two hundred eleven million, one hundred thirty-three thousand, one hundred twenty-one".