66478393 has 2 divisors, whose sum is σ = 66478394. Its totient is φ = 66478392.

The previous prime is 66478333. The next prime is 66478417. The reversal of 66478393 is 39387466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 40793769 + 25684624 = 6387^2 + 5068^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66478393 is a prime.

It is not a weakly prime, because it can be changed into another prime (66478333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33239196 + 33239197.

It is an arithmetic number, because the mean of its divisors is an integer number (33239197).

Almost surely, 2^66478393 is an apocalyptic number.

It is an amenable number.

66478393 is a deficient number, since it is larger than the sum of its proper divisors (1).

66478393 is an equidigital number, since it uses as much as digits as its factorization.

66478393 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 46.

The square root of 66478393 is about 8153.4282973483. The cubic root of 66478393 is about 405.0980669903.

The spelling of 66478393 in words is "sixty-six million, four hundred seventy-eight thousand, three hundred ninety-three".