13778709 has 8 divisors (see below), whose sum is σ = 20996160. Its totient is φ = 7873536.

The previous prime is 13778671. The next prime is 13778717. The reversal of 13778709 is 90787731.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 13778709 - 2¹⁷ = 13647637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13778759) 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 in 7 ways as a sum of consecutive naturals, for example, 328044 + ... + 328085.

It is an arithmetic number, because the mean of its divisors is an integer number (2624520).

Almost surely, 2^13778709 is an apocalyptic number.

It is an amenable number.

13778709 is a deficient number, since it is larger than the sum of its proper divisors (7217451).

13778709 is an equidigital number, since it uses as much as digits as its factorization.

13778709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656139.

The product of its (nonzero) digits is 74088, while the sum is 42.

The square root of 13778709 is about 3711.9683457702. The cubic root of 13778709 is about 239.7376125469.

The spelling of 13778709 in words is "thirteen million, seven hundred seventy-eight thousand, seven hundred nine".