13561645 has 4 divisors (see below), whose sum is σ = 16273980. Its totient is φ = 10849312.

The previous prime is 13561621. The next prime is 13561657. The reversal of 13561645 is 54616531.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2292196 + 11269449 = 1514^2 + 3357^2 .

It is a cyclic number.

It is not a de Polignac number, because 13561645 - 2¹³ = 13553453 is a prime.

It is a super-3 number, since 3×13561645³ (a number of 22 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1356160 + ... + 1356169.

It is an arithmetic number, because the mean of its divisors is an integer number (4068495).

Almost surely, 2^13561645 is an apocalyptic number.

It is an amenable number.

13561645 is a deficient number, since it is larger than the sum of its proper divisors (2712335).

13561645 is an equidigital number, since it uses as much as digits as its factorization.

13561645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2712334.

The product of its digits is 10800, while the sum is 31.

The square root of 13561645 is about 3682.6138814706. The cubic root of 13561645 is about 238.4720347177.

The spelling of 13561645 in words is "thirteen million, five hundred sixty-one thousand, six hundred forty-five".