216840133 has 4 divisors (see below), whose sum is σ = 223835008. Its totient is φ = 209845260.

The previous prime is 216840121. The next prime is 216840137. The reversal of 216840133 is 331048612.

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 216840133 - 2⁹ = 216839621 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216840137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3497391 + ... + 3497452.

It is an arithmetic number, because the mean of its divisors is an integer number (55958752).

Almost surely, 2^216840133 is an apocalyptic number.

It is an amenable number.

216840133 is a deficient number, since it is larger than the sum of its proper divisors (6994875).

216840133 is an equidigital number, since it uses as much as digits as its factorization.

216840133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6994874.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 216840133 is about 14725.4926233386. The cubic root of 216840133 is about 600.7768945499.

Adding to 216840133 its reverse (331048612), we get a palindrome (547888745).

The spelling of 216840133 in words is "two hundred sixteen million, eight hundred forty thousand, one hundred thirty-three".