66278539 has 2 divisors, whose sum is σ = 66278540. Its totient is φ = 66278538.

The previous prime is 66278491. The next prime is 66278557. The reversal of 66278539 is 93587266.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66278539 - 2¹¹ = 66276491 is a prime.

It is not a weakly prime, because it can be changed into another prime (66278579) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33139269 + 33139270.

It is an arithmetic number, because the mean of its divisors is an integer number (33139270).

Almost surely, 2^66278539 is an apocalyptic number.

66278539 is a deficient number, since it is larger than the sum of its proper divisors (1).

66278539 is an equidigital number, since it uses as much as digits as its factorization.

66278539 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 544320, while the sum is 46.

The square root of 66278539 is about 8141.1632461215. The cubic root of 66278539 is about 404.6917107208.

The spelling of 66278539 in words is "sixty-six million, two hundred seventy-eight thousand, five hundred thirty-nine".