13809645 has 24 divisors (see below), whose sum is σ = 24028056. Its totient is φ = 7337088.

The previous prime is 13809643. The next prime is 13809647. The reversal of 13809645 is 54690831.

13809645 is a `hidden beast` number, since 1 + 3 + 8 + 0 + 9 + 645 = 666.

It is an interprime number because it is at equal distance from previous prime (13809643) and next prime (13809647).

It can be written as a sum of positive squares in 4 ways, for example, as 281961 + 13527684 = 531^2 + 3678^2 .

It is not a de Polignac number, because 13809645 - 2¹ = 13809643 is a prime.

It is a super-3 number, since 3×13809645³ (a number of 22 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13809641) 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, 17479 + ... + 18251.

It is an arithmetic number, because the mean of its divisors is an integer number (1001169).

Almost surely, 2^13809645 is an apocalyptic number.

13809645 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

13809645 is a deficient number, since it is larger than the sum of its proper divisors (10218411).

13809645 is a wasteful number, since it uses less digits than its factorization.

13809645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1181 (or 1178 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 13809645 is about 3716.1330708143. The cubic root of 13809645 is about 239.9168983121.

It can be divided in two parts, 1380 and 9645, that added together give a square (11025 = 105²).

The spelling of 13809645 in words is "thirteen million, eight hundred nine thousand, six hundred forty-five".