216393251 has 2 divisors, whose sum is σ = 216393252. Its totient is φ = 216393250.

The previous prime is 216393239. The next prime is 216393253. The reversal of 216393251 is 152393612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 216393251 - 2¹⁰ = 216392227 is a prime.

Together with 216393253, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (216393253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108196625 + 108196626.

It is an arithmetic number, because the mean of its divisors is an integer number (108196626).

Almost surely, 2^216393251 is an apocalyptic number.

216393251 is a deficient number, since it is larger than the sum of its proper divisors (1).

216393251 is an equidigital number, since it uses as much as digits as its factorization.

216393251 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9720, while the sum is 32.

The square root of 216393251 is about 14710.3110436184. The cubic root of 216393251 is about 600.3639005457.

The spelling of 216393251 in words is "two hundred sixteen million, three hundred ninety-three thousand, two hundred fifty-one".