216320399 has 2 divisors, whose sum is σ = 216320400. Its totient is φ = 216320398.

The previous prime is 216320353. The next prime is 216320413. The reversal of 216320399 is 993023612.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216320399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216320099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108160199 + 108160200.

It is an arithmetic number, because the mean of its divisors is an integer number (108160200).

Almost surely, 2^216320399 is an apocalyptic number.

216320399 is a deficient number, since it is larger than the sum of its proper divisors (1).

216320399 is an equidigital number, since it uses as much as digits as its factorization.

216320399 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17496, while the sum is 35.

The square root of 216320399 is about 14707.8346128857. The cubic root of 216320399 is about 600.2965191772.

The spelling of 216320399 in words is "two hundred sixteen million, three hundred twenty thousand, three hundred ninety-nine".