493686821 has 2 divisors, whose sum is σ = 493686822. Its totient is φ = 493686820.

The previous prime is 493686803. The next prime is 493686839. The reversal of 493686821 is 128686394.

It is a balanced prime because it is at equal distance from previous prime (493686803) and next prime (493686839).

It can be written as a sum of positive squares in only one way, i.e., 380796196 + 112890625 = 19514^2 + 10625^2 .

It is a cyclic number.

It is not a de Polignac number, because 493686821 - 2⁶ = 493686757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (493686841) 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, 246843410 + 246843411.

It is an arithmetic number, because the mean of its divisors is an integer number (246843411).

Almost surely, 2^493686821 is an apocalyptic number.

It is an amenable number.

493686821 is a deficient number, since it is larger than the sum of its proper divisors (1).

493686821 is an equidigital number, since it uses as much as digits as its factorization.

493686821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 497664, while the sum is 47.

The square root of 493686821 is about 22219.0643592389. The cubic root of 493686821 is about 790.3458513462.

The spelling of 493686821 in words is "four hundred ninety-three million, six hundred eighty-six thousand, eight hundred twenty-one".