216857297 has 2 divisors, whose sum is σ = 216857298. Its totient is φ = 216857296.

The previous prime is 216857237. The next prime is 216857327. The reversal of 216857297 is 792758612.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 211731601 + 5125696 = 14551^2 + 2264^2 .

It is a cyclic number.

It is not a de Polignac number, because 216857297 - 2¹² = 216853201 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (216857237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108428648 + 108428649.

It is an arithmetic number, because the mean of its divisors is an integer number (108428649).

Almost surely, 2^216857297 is an apocalyptic number.

It is an amenable number.

216857297 is a deficient number, since it is larger than the sum of its proper divisors (1).

216857297 is an equidigital number, since it uses as much as digits as its factorization.

216857297 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 423360, while the sum is 47.

The square root of 216857297 is about 14726.0754106449. The cubic root of 216857297 is about 600.7927456478.

It can be divided in two parts, 21685 and 7297, that added together give a palindrome (28982).

The spelling of 216857297 in words is "two hundred sixteen million, eight hundred fifty-seven thousand, two hundred ninety-seven".