13817989 has 4 divisors (see below), whose sum is σ = 13826124. Its totient is φ = 13809856.

The previous prime is 13817987. The next prime is 13818017. The reversal of 13817989 is 98971831.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 98971831 = 7 ⋅14138833.

It can be written as a sum of positive squares in 2 ways, for example, as 11390625 + 2427364 = 3375^2 + 1558^2 .

It is a cyclic number.

It is not a de Polignac number, because 13817989 - 2¹ = 13817987 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 (13817987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 442 + ... + 5275.

It is an arithmetic number, because the mean of its divisors is an integer number (3456531).

Almost surely, 2^13817989 is an apocalyptic number.

It is an amenable number.

13817989 is a deficient number, since it is larger than the sum of its proper divisors (8135).

13817989 is an equidigital number, since it uses as much as digits as its factorization.

13817989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8134.

The product of its digits is 108864, while the sum is 46.

The square root of 13817989 is about 3717.2555736726. The cubic root of 13817989 is about 239.9652090772.

The spelling of 13817989 in words is "thirteen million, eight hundred seventeen thousand, nine hundred eighty-nine".