13978 has 8 divisors (see below), whose sum is σ = 21780. Its totient is φ = 6720.

The previous prime is 13967. The next prime is 13997. The reversal of 13978 is 87931.

It can be written as a sum of positive squares in 2 ways, for example, as 13689 + 289 = 117^2 + 17^2 .

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

It is a d-powerful number, because it can be written as 1 + 3⁸ + 9⁴ + 7³ + 8³ .

It is a plaindrome in base 16.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63 + ... + 178.

2¹³⁹⁷⁸ is an apocalyptic number.

13978 is a deficient number, since it is larger than the sum of its proper divisors (7802).

13978 is a wasteful number, since it uses less digits than its factorization.

13978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272.

The product of its digits is 1512, while the sum is 28.

The square root of 13978 is about 118.2285921425. The cubic root of 13978 is about 24.0887914684.

The spelling of 13978 in words is "thirteen thousand, nine hundred seventy-eight".