216665522 has 16 divisors (see below), whose sum is σ = 329153112. Its totient is φ = 106955520.

The previous prime is 216665509. The next prime is 216665551. The reversal of 216665522 is 225566612.

216665522 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 51825601 + 164839921 = 7199^2 + 12839^2 .

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, 60872 + ... + 64332.

Almost surely, 2^216665522 is an apocalyptic number.

216665522 is a deficient number, since it is larger than the sum of its proper divisors (112487590).

216665522 is a wasteful number, since it uses less digits than its factorization.

216665522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3853.

The product of its digits is 43200, while the sum is 35.

The square root of 216665522 is about 14719.5625614350. The cubic root of 216665522 is about 600.6155922683.

The spelling of 216665522 in words is "two hundred sixteen million, six hundred sixty-five thousand, five hundred twenty-two".