66216605 has 16 divisors (see below), whose sum is σ = 97797504. Its totient is φ = 41912640.

The previous prime is 66216593. The next prime is 66216607. The reversal of 66216605 is 50661266.

It is a de Polignac number, because none of the positive numbers 2^k-66216605 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66216607) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72311 + ... + 73220.

It is an arithmetic number, because the mean of its divisors is an integer number (6112344).

Almost surely, 2^66216605 is an apocalyptic number.

66216605 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

66216605 is a deficient number, since it is larger than the sum of its proper divisors (31580899).

66216605 is a wasteful number, since it uses less digits than its factorization.

66216605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145556.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 66216605 is about 8137.3586009220. The cubic root of 66216605 is about 404.5656166743.

The spelling of 66216605 in words is "sixty-six million, two hundred sixteen thousand, six hundred five".