216566506 has 16 divisors (see below), whose sum is σ = 357283584. Its totient is φ = 97826544.

The previous prime is 216566501. The next prime is 216566507. The reversal of 216566506 is 605665612.

216566506 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (216566501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87390 + ... + 89833.

It is an arithmetic number, because the mean of its divisors is an integer number (22330224).

Almost surely, 2^216566506 is an apocalyptic number.

216566506 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

216566506 is a deficient number, since it is larger than the sum of its proper divisors (140717078).

216566506 is a wasteful number, since it uses less digits than its factorization.

216566506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177285.

The product of its (nonzero) digits is 64800, while the sum is 37.

The square root of 216566506 is about 14716.1987619086. The cubic root of 216566506 is about 600.5240846847.

The spelling of 216566506 in words is "two hundred sixteen million, five hundred sixty-six thousand, five hundred six".