66855867 has 8 divisors (see below), whose sum is σ = 95998224. Its totient is φ = 41142048.

The previous prime is 66855827. The next prime is 66855881. The reversal of 66855867 is 76855866.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66855867 - 2⁷ = 66855739 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66855827) 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 in 7 ways as a sum of consecutive naturals, for example, 857088 + ... + 857165.

It is an arithmetic number, because the mean of its divisors is an integer number (11999778).

Almost surely, 2^66855867 is an apocalyptic number.

66855867 is a deficient number, since it is larger than the sum of its proper divisors (29142357).

66855867 is a wasteful number, since it uses less digits than its factorization.

66855867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1714269.

The product of its digits is 2419200, while the sum is 51.

The square root of 66855867 is about 8176.5437074598. The cubic root of 66855867 is about 405.8633556190.

Subtracting 66855867 from its reverse (76855866), we obtain a palindrome (9999999).

The spelling of 66855867 in words is "sixty-six million, eight hundred fifty-five thousand, eight hundred sixty-seven".