13388778 has 48 divisors (see below), whose sum is σ = 32334120. Its totient is φ = 3975552.

The previous prime is 13388777. The next prime is 13388779. The reversal of 13388778 is 87788331.

It is an interprime number because it is at equal distance from previous prime (13388777) and next prime (13388779).

It can be written as a sum of positive squares in 4 ways, for example, as 7469289 + 5919489 = 2733^2 + 2433^2 .

It is not an unprimeable number, because it can be changed into a prime (13388773) 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 23 ways as a sum of consecutive naturals, for example, 5800 + ... + 7772.

Almost surely, 2^13388778 is an apocalyptic number.

13388778 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 13388778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16167060).

13388778 is an abundant number, since it is smaller than the sum of its proper divisors (18945342).

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

13388778 is a wasteful number, since it uses less digits than its factorization.

13388778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2023 (or 2020 counting only the distinct ones).

The product of its digits is 225792, while the sum is 45.

The square root of 13388778 is about 3659.0679141005. The cubic root of 13388778 is about 237.4544503598.

The spelling of 13388778 in words is "thirteen million, three hundred eighty-eight thousand, seven hundred seventy-eight".