68785487909 has 2 divisors, whose sum is σ = 68785487910. Its totient is φ = 68785487908.

The previous prime is 68785487851. The next prime is 68785487921. The reversal of 68785487909 is 90978458786.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63478802500 + 5306685409 = 251950^2 + 72847^2 .

It is a cyclic number.

It is not a de Polignac number, because 68785487909 - 2²⁰ = 68784439333 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68785487509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34392743954 + 34392743955.

It is an arithmetic number, because the mean of its divisors is an integer number (34392743955).

Almost surely, 2^68785487909 is an apocalyptic number.

It is an amenable number.

68785487909 is a deficient number, since it is larger than the sum of its proper divisors (1).

68785487909 is an equidigital number, since it uses as much as digits as its factorization.

68785487909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 243855360, while the sum is 71.

The spelling of 68785487909 in words is "sixty-eight billion, seven hundred eighty-five million, four hundred eighty-seven thousand, nine hundred nine".