13921638 has 16 divisors (see below), whose sum is σ = 28120176. Its totient is φ = 4594400.

The previous prime is 13921571. The next prime is 13921643. The reversal of 13921638 is 83612931.

It is a junction number, because it is equal to n+sod(n) for n = 13921599 and 13921608.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10881 + ... + 12092.

It is an arithmetic number, because the mean of its divisors is an integer number (1757511).

Almost surely, 2^13921638 is an apocalyptic number.

13921638 is an abundant number, since it is smaller than the sum of its proper divisors (14198538).

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

13921638 is a wasteful number, since it uses less digits than its factorization.

13921638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23079.

The product of its digits is 7776, while the sum is 33.

The square root of 13921638 is about 3731.1711298197. The cubic root of 13921638 is about 240.5637096499.

The spelling of 13921638 in words is "thirteen million, nine hundred twenty-one thousand, six hundred thirty-eight".