68778709 has 4 divisors (see below), whose sum is σ = 68865804. Its totient is φ = 68691616.

The previous prime is 68778679. The next prime is 68778713. The reversal of 68778709 is 90787786.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15444900 + 53333809 = 3930^2 + 7303^2 .

It is a cyclic number.

It is not a de Polignac number, because 68778709 - 2¹³ = 68770517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68778779) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42352 + ... + 43945.

It is an arithmetic number, because the mean of its divisors is an integer number (17216451).

Almost surely, 2^68778709 is an apocalyptic number.

It is an amenable number.

68778709 is a deficient number, since it is larger than the sum of its proper divisors (87095).

68778709 is an equidigital number, since it uses as much as digits as its factorization.

68778709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87094.

The product of its (nonzero) digits is 1185408, while the sum is 52.

The square root of 68778709 is about 8293.2930130317. The cubic root of 68778709 is about 409.7176501391.

The spelling of 68778709 in words is "sixty-eight million, seven hundred seventy-eight thousand, seven hundred nine".