216066505 has 4 divisors (see below), whose sum is σ = 259279812. Its totient is φ = 172853200.

The previous prime is 216066503. The next prime is 216066517. The reversal of 216066505 is 505660612.

216066505 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 39601849 + 176464656 = 6293^2 + 13284^2 .

It is not a de Polignac number, because 216066505 - 2¹ = 216066503 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216066503) 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, 21606646 + ... + 21606655.

It is an arithmetic number, because the mean of its divisors is an integer number (64819953).

Almost surely, 2^216066505 is an apocalyptic number.

It is an amenable number.

216066505 is a deficient number, since it is larger than the sum of its proper divisors (43213307).

216066505 is an equidigital number, since it uses as much as digits as its factorization.

216066505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43213306.

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

The square root of 216066505 is about 14699.2008286165. The cubic root of 216066505 is about 600.0615723849.

The spelling of 216066505 in words is "two hundred sixteen million, sixty-six thousand, five hundred five".