216444321 has 12 divisors (see below), whose sum is σ = 313372800. Its totient is φ = 143958840.

The previous prime is 216444301. The next prime is 216444337. The reversal of 216444321 is 123444612.

It is a happy number.

216444321 is a `hidden beast` number, since 216 + 4 + 443 + 2 + 1 = 666.

It is not a de Polignac number, because 216444321 - 2¹¹ = 216442273 is a prime.

It is not an unprimeable number, because it can be changed into a prime (216444301) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24021 + ... + 31778.

It is an arithmetic number, because the mean of its divisors is an integer number (26114400).

Almost surely, 2^216444321 is an apocalyptic number.

It is an amenable number.

216444321 is a deficient number, since it is larger than the sum of its proper divisors (96928479).

216444321 is a wasteful number, since it uses less digits than its factorization.

216444321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56236 (or 56233 counting only the distinct ones).

The product of its digits is 4608, while the sum is 27.

The square root of 216444321 is about 14712.0467984574. The cubic root of 216444321 is about 600.4111265606.

Adding to 216444321 its reverse (123444612), we get a palindrome (339888933).

The spelling of 216444321 in words is "two hundred sixteen million, four hundred forty-four thousand, three hundred twenty-one".