68215729 has 2 divisors, whose sum is σ = 68215730. Its totient is φ = 68215728.

The previous prime is 68215711. The next prime is 68215783. The reversal of 68215729 is 92751286.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56655729 + 11560000 = 7527^2 + 3400^2 .

It is a cyclic number.

It is not a de Polignac number, because 68215729 - 2⁷ = 68215601 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 68215691 and 68215700.

It is not a weakly prime, because it can be changed into another prime (68215709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34107864 + 34107865.

It is an arithmetic number, because the mean of its divisors is an integer number (34107865).

Almost surely, 2^68215729 is an apocalyptic number.

It is an amenable number.

68215729 is a deficient number, since it is larger than the sum of its proper divisors (1).

68215729 is an equidigital number, since it uses as much as digits as its factorization.

68215729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 40.

The square root of 68215729 is about 8259.2813852054. The cubic root of 68215729 is about 408.5966875709.

The spelling of 68215729 in words is "sixty-eight million, two hundred fifteen thousand, seven hundred twenty-nine".