66216505 has 8 divisors (see below), whose sum is σ = 79817472. Its totient is φ = 52734768.

The previous prime is 66216499. The next prime is 66216511. The reversal of 66216505 is 50561266.

It is an interprime number because it is at equal distance from previous prime (66216499) and next prime (66216511).

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 66216505 - 2¹⁷ = 66085433 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28579 + ... + 30808.

It is an arithmetic number, because the mean of its divisors is an integer number (9977184).

Almost surely, 2^66216505 is an apocalyptic number.

It is an amenable number.

66216505 is a deficient number, since it is larger than the sum of its proper divisors (13600967).

66216505 is a wasteful number, since it uses less digits than its factorization.

66216505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59615.

The product of its (nonzero) digits is 10800, while the sum is 31.

The square root of 66216505 is about 8137.3524564197. The cubic root of 66216505 is about 404.5654130165.

The spelling of 66216505 in words is "sixty-six million, two hundred sixteen thousand, five hundred five".