66745507 has 4 divisors (see below), whose sum is σ = 66816936. Its totient is φ = 66674080.

The previous prime is 66745493. The next prime is 66745513. The reversal of 66745507 is 70554766.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66745507 - 2¹⁹ = 66221219 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66745507.

It is not an unprimeable number, because it can be changed into a prime (66745207) 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, 34294 + ... + 36187.

It is an arithmetic number, because the mean of its divisors is an integer number (16704234).

Almost surely, 2^66745507 is an apocalyptic number.

66745507 is a deficient number, since it is larger than the sum of its proper divisors (71429).

66745507 is an equidigital number, since it uses as much as digits as its factorization.

66745507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71428.

The product of its (nonzero) digits is 176400, while the sum is 40.

The square root of 66745507 is about 8169.7923474223. The cubic root of 66745507 is about 405.6399110143.

The spelling of 66745507 in words is "sixty-six million, seven hundred forty-five thousand, five hundred seven".