216604811 has 4 divisors (see below), whose sum is σ = 221213472. Its totient is φ = 211996152.

The previous prime is 216604789. The next prime is 216604831. The reversal of 216604811 is 118406612.

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

It is a cyclic number.

It is not a de Polignac number, because 216604811 - 2¹⁸ = 216342667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216604831) 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, 2304260 + ... + 2304353.

It is an arithmetic number, because the mean of its divisors is an integer number (55303368).

Almost surely, 2^216604811 is an apocalyptic number.

216604811 is a deficient number, since it is larger than the sum of its proper divisors (4608661).

216604811 is an equidigital number, since it uses as much as digits as its factorization.

216604811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4608660.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 216604811 is about 14717.5001613725. The cubic root of 216604811 is about 600.5594883111.

The spelling of 216604811 in words is "two hundred sixteen million, six hundred four thousand, eight hundred eleven".