216600385 has 8 divisors (see below), whose sum is σ = 260263080. Its totient is φ = 173051904.

The previous prime is 216600367. The next prime is 216600401. The reversal of 216600385 is 583006612.

It can be written as a sum of positive squares in 4 ways, for example, as 863041 + 215737344 = 929^2 + 14688^2 .

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 216600385 - 2⁵ = 216600353 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24322 + ... + 32011.

It is an arithmetic number, because the mean of its divisors is an integer number (32532885).

Almost surely, 2^216600385 is an apocalyptic number.

It is an amenable number.

216600385 is a deficient number, since it is larger than the sum of its proper divisors (43662695).

216600385 is an equidigital number, since it uses as much as digits as its factorization.

216600385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57107.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 216600385 is about 14717.3497953945. The cubic root of 216600385 is about 600.5553977673. Note that the first 3 decimals are identical.

Adding to 216600385 its reverse (583006612), we get a palindrome (799606997).

The spelling of 216600385 in words is "two hundred sixteen million, six hundred thousand, three hundred eighty-five".