13215561 has 8 divisors (see below), whose sum is σ = 18228480. Its totient is φ = 8506512.

The previous prime is 13215541. The next prime is 13215569. The reversal of 13215561 is 16551231.

13215561 is nontrivially palindromic in base 11.

13215561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 13215561 - 2⁹ = 13215049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13215569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75865 + ... + 76038.

It is an arithmetic number, because the mean of its divisors is an integer number (2278560).

Almost surely, 2^13215561 is an apocalyptic number.

It is an amenable number.

13215561 is a deficient number, since it is larger than the sum of its proper divisors (5012919).

13215561 is a wasteful number, since it uses less digits than its factorization.

13215561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151935.

The product of its digits is 900, while the sum is 24.

The square root of 13215561 is about 3635.3213062947. The cubic root of 13215561 is about 236.4259818100.

Adding to 13215561 its reverse (16551231), we get a palindrome (29766792).

The spelling of 13215561 in words is "thirteen million, two hundred fifteen thousand, five hundred sixty-one".