13999986 has 192 divisors, whose sum is σ = 43666560. Its totient is φ = 3265920.

The previous prime is 13999981. The next prime is 14000029. The reversal of 13999986 is 68999931.

13999986 is a nontrivial binomial coefficient, being equal to C(5292, 2).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13999981) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 378360 + ... + 378396.

It is an arithmetic number, because the mean of its divisors is an integer number (227430).

Almost surely, 2^13999986 is an apocalyptic number.

13999986 is the 5291-st triangular number and also the 2646-th hexagonal number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13999986, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21833280).

13999986 is an abundant number, since it is smaller than the sum of its proper divisors (29666574).

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

13999986 is a wasteful number, since it uses less digits than its factorization.

13999986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86 (or 73 counting only the distinct ones).

The product of its digits is 944784, while the sum is 54.

The square root of 13999986 is about 3741.6555159448. The cubic root of 13999986 is about 241.0141460794.

Subtracting 13999986 from its reverse (68999931), we obtain a palindrome (54999945).

It can be divided in two parts, 13 and 999986, that added together give a palindrome (999999).

The spelling of 13999986 in words is "thirteen million, nine hundred ninety-nine thousand, nine hundred eighty-six".