66870247 has 2 divisors, whose sum is σ = 66870248. Its totient is φ = 66870246.

The previous prime is 66870233. The next prime is 66870277. The reversal of 66870247 is 74207866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66870247 - 2⁷ = 66870119 is a prime.

It is a Chen prime.

It is equal to p_3944587 and since 66870247 and 3944587 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66870217) 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, 33435123 + 33435124.

It is an arithmetic number, because the mean of its divisors is an integer number (33435124).

Almost surely, 2^66870247 is an apocalyptic number.

66870247 is a deficient number, since it is larger than the sum of its proper divisors (1).

66870247 is an equidigital number, since it uses as much as digits as its factorization.

66870247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112896, while the sum is 40.

The square root of 66870247 is about 8177.4230048347. The cubic root of 66870247 is about 405.8924525251.

The spelling of 66870247 in words is "sixty-six million, eight hundred seventy thousand, two hundred forty-seven".