66685457 has 2 divisors, whose sum is σ = 66685458. Its totient is φ = 66685456.

The previous prime is 66685447. The next prime is 66685469. The reversal of 66685457 is 75458666.

66685457 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64657681 + 2027776 = 8041^2 + 1424^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66685457 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66685447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33342728 + 33342729.

It is an arithmetic number, because the mean of its divisors is an integer number (33342729).

Almost surely, 2^66685457 is an apocalyptic number.

It is an amenable number.

66685457 is a deficient number, since it is larger than the sum of its proper divisors (1).

66685457 is an equidigital number, since it uses as much as digits as its factorization.

66685457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1209600, while the sum is 47.

The square root of 66685457 is about 8166.1163964274. The cubic root of 66685457 is about 405.5182249939.

The spelling of 66685457 in words is "sixty-six million, six hundred eighty-five thousand, four hundred fifty-seven".