66708739 has 2 divisors, whose sum is σ = 66708740. Its totient is φ = 66708738.

The previous prime is 66708727. The next prime is 66708779. The reversal of 66708739 is 93780766.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66708739 - 2⁷ = 66708611 is a prime.

It is not a weakly prime, because it can be changed into another prime (66708709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33354369 + 33354370.

It is an arithmetic number, because the mean of its divisors is an integer number (33354370).

Almost surely, 2^66708739 is an apocalyptic number.

66708739 is a deficient number, since it is larger than the sum of its proper divisors (1).

66708739 is an equidigital number, since it uses as much as digits as its factorization.

66708739 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 381024, while the sum is 46.

The square root of 66708739 is about 8167.5417966485. The cubic root of 66708739 is about 405.5654125778.

The spelling of 66708739 in words is "sixty-six million, seven hundred eight thousand, seven hundred thirty-nine".