13639680 has 168 divisors, whose sum is σ = 48559212. Its totient is φ = 3538944.

The previous prime is 13639651. The next prime is 13639693. The reversal of 13639680 is 8693631.

It is a happy number.

13639680 is a `hidden beast` number, since 13 + 639 + 6 + 8 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 13307904 + 331776 = 3648^2 + 576^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 368622 + ... + 368658.

Almost surely, 2^13639680 is an apocalyptic number.

13639680 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 13639680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24279606).

13639680 is an abundant number, since it is smaller than the sum of its proper divisors (34919532).

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

13639680 is an equidigital number, since it uses as much as digits as its factorization.

13639680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74 (or 47 counting only the distinct ones).

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

The square root of 13639680 is about 3693.1937398409. The cubic root of 13639680 is about 238.9285571608.

The spelling of 13639680 in words is "thirteen million, six hundred thirty-nine thousand, six hundred eighty".