13011561 has 12 divisors (see below), whose sum is σ = 19783920. Its totient is φ = 8217720.

The previous prime is 13011541. The next prime is 13011563. The reversal of 13011561 is 16511031.

It is not a de Polignac number, because 13011561 - 2⁵ = 13011529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13011563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37875 + ... + 38216.

It is an arithmetic number, because the mean of its divisors is an integer number (1648660).

Almost surely, 2^13011561 is an apocalyptic number.

It is an amenable number.

13011561 is a deficient number, since it is larger than the sum of its proper divisors (6772359).

13011561 is a wasteful number, since it uses less digits than its factorization.

13011561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76116 (or 76113 counting only the distinct ones).

The product of its (nonzero) digits is 90, while the sum is 18.

The square root of 13011561 is about 3607.1541414251. The cubic root of 13011561 is about 235.2031501209.

Adding to 13011561 its reverse (16511031), we get a palindrome (29522592).

The spelling of 13011561 in words is "thirteen million, eleven thousand, five hundred sixty-one".