66723539 has 2 divisors, whose sum is σ = 66723540. Its totient is φ = 66723538.

The previous prime is 66723509. The next prime is 66723583. The reversal of 66723539 is 93532766.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66723539 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66723496 and 66723505.

It is not a weakly prime, because it can be changed into another prime (66723509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33361769 + 33361770.

It is an arithmetic number, because the mean of its divisors is an integer number (33361770).

Almost surely, 2^66723539 is an apocalyptic number.

66723539 is a deficient number, since it is larger than the sum of its proper divisors (1).

66723539 is an equidigital number, since it uses as much as digits as its factorization.

66723539 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 204120, while the sum is 41.

The square root of 66723539 is about 8168.4477717618. The cubic root of 66723539 is about 405.5954032724.

The spelling of 66723539 in words is "sixty-six million, seven hundred twenty-three thousand, five hundred thirty-nine".