494540821 has 2 divisors, whose sum is σ = 494540822. Its totient is φ = 494540820.

The previous prime is 494540777. The next prime is 494540831. The reversal of 494540821 is 128045494.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 335402596 + 159138225 = 18314^2 + 12615^2 .

It is a cyclic number.

It is not a de Polignac number, because 494540821 - 2⁹ = 494540309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (494540831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 247270410 + 247270411.

It is an arithmetic number, because the mean of its divisors is an integer number (247270411).

Almost surely, 2^494540821 is an apocalyptic number.

It is an amenable number.

494540821 is a deficient number, since it is larger than the sum of its proper divisors (1).

494540821 is an equidigital number, since it uses as much as digits as its factorization.

494540821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46080, while the sum is 37.

The square root of 494540821 is about 22238.2737864251. The cubic root of 494540821 is about 790.8013131986.

The spelling of 494540821 in words is "four hundred ninety-four million, five hundred forty thousand, eight hundred twenty-one".