13685778 has 12 divisors (see below), whose sum is σ = 29652558. Its totient is φ = 4561920.

The previous prime is 13685773. The next prime is 13685783. The reversal of 13685778 is 87758631.

13685778 is a `hidden beast` number, since 13 + 68 + 577 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (13685773) and next prime (13685783).

It can be written as a sum of positive squares in only one way, i.e., 13593969 + 91809 = 3687^2 + 303^2 .

It is not an unprimeable number, because it can be changed into a prime (13685773) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 380143 + ... + 380178.

Almost surely, 2^13685778 is an apocalyptic number.

13685778 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

13685778 is an abundant number, since it is smaller than the sum of its proper divisors (15966780).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13685778 is a wasteful number, since it uses less digits than its factorization.

13685778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 760329 (or 760326 counting only the distinct ones).

The product of its digits is 282240, while the sum is 45.

The square root of 13685778 is about 3699.4294154640. The cubic root of 13685778 is about 239.1974232859.

The spelling of 13685778 in words is "thirteen million, six hundred eighty-five thousand, seven hundred seventy-eight".