216730993 has 2 divisors, whose sum is σ = 216730994. Its totient is φ = 216730992.

The previous prime is 216730973. The next prime is 216731003. The reversal of 216730993 is 399037612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 160959969 + 55771024 = 12687^2 + 7468^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216730993 is a prime.

It is not a weakly prime, because it can be changed into another prime (216730963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108365496 + 108365497.

It is an arithmetic number, because the mean of its divisors is an integer number (108365497).

Almost surely, 2^216730993 is an apocalyptic number.

It is an amenable number.

216730993 is a deficient number, since it is larger than the sum of its proper divisors (1).

216730993 is an equidigital number, since it uses as much as digits as its factorization.

216730993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 61236, while the sum is 40.

The square root of 216730993 is about 14721.7863386207. The cubic root of 216730993 is about 600.6760832699.

The spelling of 216730993 in words is "two hundred sixteen million, seven hundred thirty thousand, nine hundred ninety-three".