216641729 has 2 divisors, whose sum is σ = 216641730. Its totient is φ = 216641728.

The previous prime is 216641717. The next prime is 216641759. The reversal of 216641729 is 927146612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 149401729 + 67240000 = 12223^2 + 8200^2 .

It is a cyclic number.

It is not a de Polignac number, because 216641729 - 2⁴ = 216641713 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 216641692 and 216641701.

It is not a weakly prime, because it can be changed into another prime (216641759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108320864 + 108320865.

It is an arithmetic number, because the mean of its divisors is an integer number (108320865).

Almost surely, 2^216641729 is an apocalyptic number.

It is an amenable number.

216641729 is a deficient number, since it is larger than the sum of its proper divisors (1).

216641729 is an equidigital number, since it uses as much as digits as its factorization.

216641729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 38.

The square root of 216641729 is about 14718.7543290864. The cubic root of 216641729 is about 600.5936060446.

The spelling of 216641729 in words is "two hundred sixteen million, six hundred forty-one thousand, seven hundred twenty-nine".