13216861 has 4 divisors (see below), whose sum is σ = 15104992. Its totient is φ = 11328732.

The previous prime is 13216843. The next prime is 13216873. The reversal of 13216861 is 16861231.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16861231 = 23 ⋅733097.

It is a cyclic number.

It is not a de Polignac number, because 13216861 - 2¹¹ = 13214813 is a prime.

It is the 3636-th Hogben number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13216831) by changing a digit.

It is a nontrivial repunit in base 3635.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 944055 + ... + 944068.

It is an arithmetic number, because the mean of its divisors is an integer number (3776248).

Almost surely, 2^13216861 is an apocalyptic number.

It is an amenable number.

13216861 is a deficient number, since it is larger than the sum of its proper divisors (1888131).

13216861 is an equidigital number, since it uses as much as digits as its factorization.

13216861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1888130.

The product of its digits is 1728, while the sum is 28.

The square root of 13216861 is about 3635.5001031495. The cubic root of 13216861 is about 236.4337338759.

The spelling of 13216861 in words is "thirteen million, two hundred sixteen thousand, eight hundred sixty-one".