216434321 has 4 divisors (see below), whose sum is σ = 219664752. Its totient is φ = 213203892.

The previous prime is 216434297. The next prime is 216434333. The reversal of 216434321 is 123434612.

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 216434321 - 2¹⁴ = 216417937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216434371) 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, 1615115 + ... + 1615248.

It is an arithmetic number, because the mean of its divisors is an integer number (54916188).

Almost surely, 2^216434321 is an apocalyptic number.

It is an amenable number.

216434321 is a deficient number, since it is larger than the sum of its proper divisors (3230431).

216434321 is an equidigital number, since it uses as much as digits as its factorization.

216434321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3230430.

The product of its digits is 3456, while the sum is 26.

The square root of 216434321 is about 14711.7069369941. The cubic root of 216434321 is about 600.4018798350.

Adding to 216434321 its reverse (123434612), we get a palindrome (339868933).

The spelling of 216434321 in words is "two hundred sixteen million, four hundred thirty-four thousand, three hundred twenty-one".