66813859 has 8 divisors (see below), whose sum is σ = 80850528. Its totient is φ = 53900160.

The previous prime is 66813853. The next prime is 66813889. The reversal of 66813859 is 95831866.

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

It is a cyclic number.

It is not a de Polignac number, because 66813859 - 2⁹ = 66813347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66813853) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 280612 + ... + 280849.

It is an arithmetic number, because the mean of its divisors is an integer number (10106316).

Almost surely, 2^66813859 is an apocalyptic number.

66813859 is a deficient number, since it is larger than the sum of its proper divisors (14036669).

66813859 is a wasteful number, since it uses less digits than its factorization.

66813859 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 561485.

The product of its digits is 311040, while the sum is 46.

The square root of 66813859 is about 8173.9744922528. The cubic root of 66813859 is about 405.7783315176.

The spelling of 66813859 in words is "sixty-six million, eight hundred thirteen thousand, eight hundred fifty-nine".