13987638 has 36 divisors (see below), whose sum is σ = 35256780. Its totient is φ = 3996216.

The previous prime is 13987627. The next prime is 13987663. The reversal of 13987638 is 83678931.

It is a happy number.

13987638 is a `hidden beast` number, since 1 + 3 + 9 + 8 + 7 + 638 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 13987593 and 13987602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 7048 + ... + 8811.

It is an arithmetic number, because the mean of its divisors is an integer number (979355).

Almost surely, 2^13987638 is an apocalyptic number.

13987638 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

13987638 is an abundant number, since it is smaller than the sum of its proper divisors (21269142).

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

13987638 is a wasteful number, since it uses less digits than its factorization.

13987638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15881 (or 15871 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 13987638 is about 3740.0050802105. The cubic root of 13987638 is about 240.9432670071.

The spelling of 13987638 in words is "thirteen million, nine hundred eighty-seven thousand, six hundred thirty-eight".