13680639 has 24 divisors (see below), whose sum is σ = 23198240. Its totient is φ = 7604928.

The previous prime is 13680637. The next prime is 13680643. The reversal of 13680639 is 93608631.

It is a happy number.

13680639 is a `hidden beast` number, since 13 + 6 + 8 + 0 + 639 = 666.

It is not a de Polignac number, because 13680639 - 2¹ = 13680637 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 (13680637) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 604 + ... + 5265.

Almost surely, 2^13680639 is an apocalyptic number.

13680639 is a deficient number, since it is larger than the sum of its proper divisors (9517601).

13680639 is a wasteful number, since it uses less digits than its factorization.

13680639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5919 (or 5916 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 13680639 is about 3698.7347836794. The cubic root of 13680639 is about 239.1674800497.

The spelling of 13680639 in words is "thirteen million, six hundred eighty thousand, six hundred thirty-nine".