66806903 has 4 divisors (see below), whose sum is σ = 67652640. Its totient is φ = 65961168.

The previous prime is 66806851. The next prime is 66806921. The reversal of 66806903 is 30960866.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 30960866 = 2 ⋅15480433.

It is a cyclic number.

It is not a de Polignac number, because 66806903 - 2²⁴ = 50029687 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66806503) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 422750 + ... + 422907.

It is an arithmetic number, because the mean of its divisors is an integer number (16913160).

Almost surely, 2^66806903 is an apocalyptic number.

66806903 is a deficient number, since it is larger than the sum of its proper divisors (845737).

66806903 is an equidigital number, since it uses as much as digits as its factorization.

66806903 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 845736.

The product of its (nonzero) digits is 46656, while the sum is 38.

The square root of 66806903 is about 8173.5489843764. The cubic root of 66806903 is about 405.7642491497.

The spelling of 66806903 in words is "sixty-six million, eight hundred six thousand, nine hundred three".