216188729 has 2 divisors, whose sum is σ = 216188730. Its totient is φ = 216188728.

The previous prime is 216188683. The next prime is 216188737. The reversal of 216188729 is 927881612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 215414329 + 774400 = 14677^2 + 880^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216188729 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 216188729.

It is not a weakly prime, because it can be changed into another prime (216188789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108094364 + 108094365.

It is an arithmetic number, because the mean of its divisors is an integer number (108094365).

Almost surely, 2^216188729 is an apocalyptic number.

It is an amenable number.

216188729 is a deficient number, since it is larger than the sum of its proper divisors (1).

216188729 is an equidigital number, since it uses as much as digits as its factorization.

216188729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 44.

The square root of 216188729 is about 14703.3577457668. The cubic root of 216188729 is about 600.1746982034.

The spelling of 216188729 in words is "two hundred sixteen million, one hundred eighty-eight thousand, seven hundred twenty-nine".