66806387 has 2 divisors, whose sum is σ = 66806388. Its totient is φ = 66806386.

The previous prime is 66806359. The next prime is 66806431. The reversal of 66806387 is 78360866.

It is an a-pointer prime, because the next prime (66806431) can be obtained adding 66806387 to its sum of digits (44).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66806387 - 2⁶ = 66806323 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66806347) 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, 33403193 + 33403194.

It is an arithmetic number, because the mean of its divisors is an integer number (33403194).

Almost surely, 2^66806387 is an apocalyptic number.

66806387 is a deficient number, since it is larger than the sum of its proper divisors (1).

66806387 is an equidigital number, since it uses as much as digits as its factorization.

66806387 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 290304, while the sum is 44.

The square root of 66806387 is about 8173.5174190797. The cubic root of 66806387 is about 405.7632044728.

The spelling of 66806387 in words is "sixty-six million, eight hundred six thousand, three hundred eighty-seven".