66673613 has 2 divisors, whose sum is σ = 66673614. Its totient is φ = 66673612.

The previous prime is 66673583. The next prime is 66673631. The reversal of 66673613 is 31637666.

Together with next prime (66673631) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39664804 + 27008809 = 6298^2 + 5197^2 .

66673613 is a truncatable prime.

It is a cyclic number.

It is not a de Polignac number, because 66673613 - 2¹⁴ = 66657229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66675613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33336806 + 33336807.

It is an arithmetic number, because the mean of its divisors is an integer number (33336807).

Almost surely, 2^66673613 is an apocalyptic number.

It is an amenable number.

66673613 is a deficient number, since it is larger than the sum of its proper divisors (1).

66673613 is an equidigital number, since it uses as much as digits as its factorization.

66673613 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81648, while the sum is 38.

The square root of 66673613 is about 8165.3911725036. The cubic root of 66673613 is about 405.4942155499.

The spelling of 66673613 in words is "sixty-six million, six hundred seventy-three thousand, six hundred thirteen".