13203561 has 16 divisors (see below), whose sum is σ = 20664704. Its totient is φ = 7340544.

The previous prime is 13203527. The next prime is 13203563. The reversal of 13203561 is 16530231.

13203561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 13203561 - 2¹⁴ = 13187177 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13203563) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7720 + ... + 9273.

It is an arithmetic number, because the mean of its divisors is an integer number (1291544).

Almost surely, 2^13203561 is an apocalyptic number.

It is an amenable number.

13203561 is a deficient number, since it is larger than the sum of its proper divisors (7461143).

13203561 is a wasteful number, since it uses less digits than its factorization.

13203561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17040.

The product of its (nonzero) digits is 540, while the sum is 21.

The square root of 13203561 is about 3633.6704583658. The cubic root of 13203561 is about 236.3544002622.

Adding to 13203561 its reverse (16530231), we get a palindrome (29733792).

The spelling of 13203561 in words is "thirteen million, two hundred three thousand, five hundred sixty-one".