13938640 has 80 divisors (see below), whose sum is σ = 35368272. Its totient is φ = 5087232.

The previous prime is 13938581. The next prime is 13938671. The reversal of 13938640 is 4683931.

It can be written as a sum of positive squares in 8 ways, for example, as 219024 + 13719616 = 468^2 + 3704^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 13938596 and 13938605.

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 15 ways as a sum of consecutive naturals, for example, 50182 + ... + 50458.

Almost surely, 2^13938640 is an apocalyptic number.

13938640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13938640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17684136).

13938640 is an abundant number, since it is smaller than the sum of its proper divisors (21429632).

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

13938640 is a wasteful number, since it uses less digits than its factorization.

13938640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344 (or 338 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 13938640 is about 3733.4488077380. The cubic root of 13938640 is about 240.6616004370.

The spelling of 13938640 in words is "thirteen million, nine hundred thirty-eight thousand, six hundred forty".