216506633 has 4 divisors (see below), whose sum is σ = 247436160. Its totient is φ = 185577108.

The previous prime is 216506623. The next prime is 216506639. The reversal of 216506633 is 336605612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 216506633 - 2⁴ = 216506617 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 216506633.

It is not an unprimeable number, because it can be changed into a prime (216506639) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 15464753 + ... + 15464766.

It is an arithmetic number, because the mean of its divisors is an integer number (61859040).

Almost surely, 2^216506633 is an apocalyptic number.

It is an amenable number.

216506633 is a deficient number, since it is larger than the sum of its proper divisors (30929527).

216506633 is an equidigital number, since it uses as much as digits as its factorization.

216506633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30929526.

The product of its (nonzero) digits is 19440, while the sum is 32.

The square root of 216506633 is about 14714.1643663512. The cubic root of 216506633 is about 600.4687383415.

The spelling of 216506633 in words is "two hundred sixteen million, five hundred six thousand, six hundred thirty-three".