66851865 has 16 divisors (see below), whose sum is σ = 118848000. Its totient is φ = 35654256.

The previous prime is 66851849. The next prime is 66851879. The reversal of 66851865 is 56815866.

66851865 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 66851865 - 2⁴ = 66851849 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 66851865.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 247465 + ... + 247734.

It is an arithmetic number, because the mean of its divisors is an integer number (7428000).

Almost surely, 2^66851865 is an apocalyptic number.

It is an amenable number.

66851865 is a deficient number, since it is larger than the sum of its proper divisors (51996135).

66851865 is a wasteful number, since it uses less digits than its factorization.

66851865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 495213 (or 495207 counting only the distinct ones).

The product of its digits is 345600, while the sum is 45.

The square root of 66851865 is about 8176.2989793671. The cubic root of 66851865 is about 405.8552571148.

The spelling of 66851865 in words is "sixty-six million, eight hundred fifty-one thousand, eight hundred sixty-five".