13321561 has 4 divisors (see below), whose sum is σ = 14532624. Its totient is φ = 12110500.

The previous prime is 13321559. The next prime is 13321579. The reversal of 13321561 is 16512331.

It is a happy number.

13321561 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 13321561 - 2¹ = 13321559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13321361) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 605515 + ... + 605536.

It is an arithmetic number, because the mean of its divisors is an integer number (3633156).

Almost surely, 2^13321561 is an apocalyptic number.

13321561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

13321561 is a deficient number, since it is larger than the sum of its proper divisors (1211063).

13321561 is a wasteful number, since it uses less digits than its factorization.

13321561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1211062.

The product of its digits is 540, while the sum is 22.

The square root of 13321561 is about 3649.8713675964. The cubic root of 13321561 is about 237.0564115273.

Adding to 13321561 its reverse (16512331), we get a palindrome (29833892).

The spelling of 13321561 in words is "thirteen million, three hundred twenty-one thousand, five hundred sixty-one".