168216321 has 32 divisors (see below), whose sum is σ = 278629120. Its totient is φ = 87899904.

The previous prime is 168216289. The next prime is 168216331. The reversal of 168216321 is 123612861.

It is not a de Polignac number, because 168216321 - 2⁵ = 168216289 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (168216331) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26931 + ... + 32583.

It is an arithmetic number, because the mean of its divisors is an integer number (8707160).

Almost surely, 2^168216321 is an apocalyptic number.

It is an amenable number.

168216321 is a deficient number, since it is larger than the sum of its proper divisors (110412799).

168216321 is a wasteful number, since it uses less digits than its factorization.

168216321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5785.

The product of its digits is 3456, while the sum is 30.

The square root of 168216321 is about 12969.8234760539. The cubic root of 168216321 is about 552.0215643487.

The spelling of 168216321 in words is "one hundred sixty-eight million, two hundred sixteen thousand, three hundred twenty-one".