291191057 has 2 divisors, whose sum is σ = 291191058. Its totient is φ = 291191056.

The previous prime is 291191009. The next prime is 291191071. The reversal of 291191057 is 750191192.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 279692176 + 11498881 = 16724^2 + 3391^2 .

It is a cyclic number.

It is not a de Polignac number, because 291191057 - 2¹⁴ = 291174673 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (291199057) 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 as a sum of consecutive naturals, namely, 145595528 + 145595529.

It is an arithmetic number, because the mean of its divisors is an integer number (145595529).

Almost surely, 2^291191057 is an apocalyptic number.

It is an amenable number.

291191057 is a deficient number, since it is larger than the sum of its proper divisors (1).

291191057 is an equidigital number, since it uses as much as digits as its factorization.

291191057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5670, while the sum is 35.

The square root of 291191057 is about 17064.3211702077. The cubic root of 291191057 is about 662.8155331886.

The spelling of 291191057 in words is "two hundred ninety-one million, one hundred ninety-one thousand, fifty-seven".