291681601 has 2 divisors, whose sum is σ = 291681602. Its totient is φ = 291681600.

The previous prime is 291681581. The next prime is 291681629. The reversal of 291681601 is 106186192.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 214593201 + 77088400 = 14649^2 + 8780^2 .

It is a cyclic number.

It is not a de Polignac number, because 291681601 - 2¹³ = 291673409 is a prime.

It is not a weakly prime, because it can be changed into another prime (291681661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 145840800 + 145840801.

It is an arithmetic number, because the mean of its divisors is an integer number (145840801).

Almost surely, 2^291681601 is an apocalyptic number.

It is an amenable number.

291681601 is a deficient number, since it is larger than the sum of its proper divisors (1).

291681601 is an equidigital number, since it uses as much as digits as its factorization.

291681601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 291681601 is about 17078.6885035122. The cubic root of 291681601 is about 663.1875200880.

The spelling of 291681601 in words is "two hundred ninety-one million, six hundred eighty-one thousand, six hundred one".