291517493 has 2 divisors, whose sum is σ = 291517494. Its totient is φ = 291517492.

The previous prime is 291517489. The next prime is 291517531. The reversal of 291517493 is 394715192.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 174055249 + 117462244 = 13193^2 + 10838^2 .

It is a cyclic number.

It is not a de Polignac number, because 291517493 - 2² = 291517489 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 291517493.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (291517423) 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 as a sum of consecutive naturals, namely, 145758746 + 145758747.

It is an arithmetic number, because the mean of its divisors is an integer number (145758747).

Almost surely, 2^291517493 is an apocalyptic number.

It is an amenable number.

291517493 is a deficient number, since it is larger than the sum of its proper divisors (1).

291517493 is an equidigital number, since it uses as much as digits as its factorization.

291517493 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 68040, while the sum is 41.

The square root of 291517493 is about 17073.8833602669. The cubic root of 291517493 is about 663.0631209776.

The spelling of 291517493 in words is "two hundred ninety-one million, five hundred seventeen thousand, four hundred ninety-three".