13987378 has 4 divisors (see below), whose sum is σ = 20981070. Its totient is φ = 6993688.

The previous prime is 13987373. The next prime is 13987387. The reversal of 13987378 is 87378931.

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 only one way, i.e., 10843849 + 3143529 = 3293^2 + 1773^2 .

It is not an unprimeable number, because it can be changed into a prime (13987373) 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 as a sum of consecutive naturals, namely, 3496843 + ... + 3496846.

Almost surely, 2^13987378 is an apocalyptic number.

13987378 is a deficient number, since it is larger than the sum of its proper divisors (6993692).

13987378 is an equidigital number, since it uses as much as digits as its factorization.

13987378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6993691.

The product of its digits is 254016, while the sum is 46.

The square root of 13987378 is about 3739.9703207379. The cubic root of 13987378 is about 240.9417741260.

It can be divided in two parts, 13987 and 378, that added together give a triangular number (14365 = T₁₆₉).

The spelling of 13987378 in words is "thirteen million, nine hundred eighty-seven thousand, three hundred seventy-eight".