13878397 has 4 divisors (see below), whose sum is σ = 14945980. Its totient is φ = 12810816.

The previous prime is 13878391. The next prime is 13878413. The reversal of 13878397 is 79387831.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79387831 = 67 ⋅1184893.

It can be written as a sum of positive squares in 2 ways, for example, as 5433561 + 8444836 = 2331^2 + 2906^2 .

It is a cyclic number.

It is not a de Polignac number, because 13878397 - 2¹¹ = 13876349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13878391) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 533772 + ... + 533797.

It is an arithmetic number, because the mean of its divisors is an integer number (3736495).

Almost surely, 2^13878397 is an apocalyptic number.

It is an amenable number.

13878397 is a deficient number, since it is larger than the sum of its proper divisors (1067583).

13878397 is a wasteful number, since it uses less digits than its factorization.

13878397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1067582.

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

The square root of 13878397 is about 3725.3720619557. The cubic root of 13878397 is about 240.3143854480.

The spelling of 13878397 in words is "thirteen million, eight hundred seventy-eight thousand, three hundred ninety-seven".