1211121121 has 8 divisors (see below), whose sum is σ = 1389286080. Its totient is φ = 1034243088.

The previous prime is 1211121091. The next prime is 1211121139. The reversal of 1211121121 is 1211211121.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1211121121 - 2⁷ = 1211120993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1211124121) 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 7 ways as a sum of consecutive naturals, for example, 319711 + ... + 323476.

It is an arithmetic number, because the mean of its divisors is an integer number (173660760).

Almost surely, 2^1211121121 is an apocalyptic number.

It is an amenable number.

1211121121 is a deficient number, since it is larger than the sum of its proper divisors (178164959).

1211121121 is an equidigital number, since it uses as much as digits as its factorization.

1211121121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643463.

The product of its digits is 8, while the sum is 13.

The square root of 1211121121 is about 34801.1655120917. The cubic root of 1211121121 is about 1065.9312451035.

Adding to 1211121121 its reverse (1211211121), we get a palindrome (2422332242).

Subtracting 1211121121 from its reverse (1211211121), we obtain a square (90000 = 300²).

It can be divided in two parts, 1211121 and 121, that multiplied together give a palindrome (146545641).

The spelling of 1211121121 in words is "one billion, two hundred eleven million, one hundred twenty-one thousand, one hundred twenty-one".