66728335 has 4 divisors (see below), whose sum is σ = 80074008. Its totient is φ = 53382664.

The previous prime is 66728329. The next prime is 66728339. The reversal of 66728335 is 53382766.

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 66728335 - 2⁹ = 66727823 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 congruent number.

It is not an unprimeable number, because it can be changed into a prime (66728339) 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, 6672829 + ... + 6672838.

It is an arithmetic number, because the mean of its divisors is an integer number (20018502).

Almost surely, 2^66728335 is an apocalyptic number.

66728335 is a deficient number, since it is larger than the sum of its proper divisors (13345673).

66728335 is a wasteful number, since it uses less digits than its factorization.

66728335 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13345672.

The product of its digits is 181440, while the sum is 40.

The square root of 66728335 is about 8168.7413351140. The cubic root of 66728335 is about 405.6051209272.

The spelling of 66728335 in words is "sixty-six million, seven hundred twenty-eight thousand, three hundred thirty-five".