291681457 has 2 divisors, whose sum is σ = 291681458. Its totient is φ = 291681456.

The previous prime is 291681451. The next prime is 291681463. The reversal of 291681457 is 754186192.

It is a balanced prime because it is at equal distance from previous prime (291681451) and next prime (291681463).

It can be written as a sum of positive squares in only one way, i.e., 284900641 + 6780816 = 16879^2 + 2604^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-291681457 is a prime.

It is not a weakly prime, because it can be changed into another prime (291681451) 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, 145840728 + 145840729.

It is an arithmetic number, because the mean of its divisors is an integer number (145840729).

Almost surely, 2^291681457 is an apocalyptic number.

It is an amenable number.

291681457 is a deficient number, since it is larger than the sum of its proper divisors (1).

291681457 is an equidigital number, since it uses as much as digits as its factorization.

291681457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120960, while the sum is 43.

The square root of 291681457 is about 17078.6842877313. The cubic root of 291681457 is about 663.1874109518.

It can be divided in two parts, 29168 and 1457, that added together give a square (30625 = 175²).

The spelling of 291681457 in words is "two hundred ninety-one million, six hundred eighty-one thousand, four hundred fifty-seven".