1001211121 has 2 divisors, whose sum is σ = 1001211122. Its totient is φ = 1001211120.

The previous prime is 1001211089. The next prime is 1001211163. The reversal of 1001211121 is 1211121001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 922640625 + 78570496 = 30375^2 + 8864^2 .

It is a cyclic number.

It is not a de Polignac number, because 1001211121 - 2⁵ = 1001211089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1001211098 and 1001211107.

It is not a weakly prime, because it can be changed into another prime (1001211221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500605560 + 500605561.

It is an arithmetic number, because the mean of its divisors is an integer number (500605561).

Almost surely, 2^1001211121 is an apocalyptic number.

It is an amenable number.

1001211121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001211121 is an equidigital number, since it uses as much as digits as its factorization.

1001211121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4, while the sum is 10.

The square root of 1001211121 is about 31641.9203115108. The cubic root of 1001211121 is about 1000.4035441302.

Adding to 1001211121 its reverse (1211121001), we get a palindrome (2212332122).

The spelling of 1001211121 in words is "one billion, one million, two hundred eleven thousand, one hundred twenty-one".