66378534787 has 2 divisors, whose sum is σ = 66378534788. Its totient is φ = 66378534786.

The previous prime is 66378534763. The next prime is 66378534799. The reversal of 66378534787 is 78743587366.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66378534787 - 2¹⁵ = 66378502019 is a prime.

It is a super-2 number, since 2×66378534787² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66378534707) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33189267393 + 33189267394.

It is an arithmetic number, because the mean of its divisors is an integer number (33189267394).

Almost surely, 2^66378534787 is an apocalyptic number.

66378534787 is a deficient number, since it is larger than the sum of its proper divisors (1).

66378534787 is an equidigital number, since it uses as much as digits as its factorization.

66378534787 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 142248960, while the sum is 64.

The spelling of 66378534787 in words is "sixty-six billion, three hundred seventy-eight million, five hundred thirty-four thousand, seven hundred eighty-seven".