291211121 has 2 divisors, whose sum is σ = 291211122. Its totient is φ = 291211120.

The previous prime is 291211111. The next prime is 291211159. The reversal of 291211121 is 121112192.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 290327521 + 883600 = 17039^2 + 940^2 .

It is a cyclic number.

It is not a de Polignac number, because 291211121 - 2¹⁰ = 291210097 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 291211093 and 291211102.

It is not a weakly prime, because it can be changed into another prime (291211111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 145605560 + 145605561.

It is an arithmetic number, because the mean of its divisors is an integer number (145605561).

Almost surely, 2^291211121 is an apocalyptic number.

It is an amenable number.

291211121 is a deficient number, since it is larger than the sum of its proper divisors (1).

291211121 is an equidigital number, since it uses as much as digits as its factorization.

291211121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72, while the sum is 20.

The square root of 291211121 is about 17064.9090533762. The cubic root of 291211121 is about 662.8307562127.

The spelling of 291211121 in words is "two hundred ninety-one million, two hundred eleven thousand, one hundred twenty-one".