13645728 has 36 divisors (see below), whose sum is σ = 38805858. Its totient is φ = 4548480.

The previous prime is 13645727. The next prime is 13645757. The reversal of 13645728 is 82754631.

13645728 is a `hidden beast` number, since 1 + 3 + 645 + 7 + 2 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 8928144 + 4717584 = 2988^2 + 2172^2 .

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a junction number, because it is equal to n+sod(n) for n = 13645692 and 13645701.

It is not an unprimeable number, because it can be changed into a prime (13645727) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 23403 + ... + 23978.

Almost surely, 2^13645728 is an apocalyptic number.

13645728 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

13645728 is an abundant number, since it is smaller than the sum of its proper divisors (25160130).

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

13645728 is a wasteful number, since it uses less digits than its factorization.

13645728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47397 (or 47386 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 13645728 is about 3694.0124526049. The cubic root of 13645728 is about 238.9638665518.

The spelling of 13645728 in words is "thirteen million, six hundred forty-five thousand, seven hundred twenty-eight".