66871019 has 2 divisors, whose sum is σ = 66871020. Its totient is φ = 66871018.

The previous prime is 66871009. The next prime is 66871033. The reversal of 66871019 is 91017866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66871019 - 2⁴ = 66871003 is a prime.

It is a super-2 number, since 2×66871019² = 8943466364196722, which contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (66871009) 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, 33435509 + 33435510.

It is an arithmetic number, because the mean of its divisors is an integer number (33435510).

Almost surely, 2^66871019 is an apocalyptic number.

66871019 is a deficient number, since it is larger than the sum of its proper divisors (1).

66871019 is an equidigital number, since it uses as much as digits as its factorization.

66871019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 66871019 is about 8177.4702078332. The cubic root of 66871019 is about 405.8940144942.

The spelling of 66871019 in words is "sixty-six million, eight hundred seventy-one thousand, nineteen".