13086721 has 4 divisors (see below), whose sum is σ = 13125892. Its totient is φ = 13047552.

The previous prime is 13086713. The next prime is 13086737. The reversal of 13086721 is 12768031.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3101121 + 9985600 = 1761^2 + 3160^2 .

It is a cyclic number.

It is not a de Polignac number, because 13086721 - 2³ = 13086713 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13086721.

It is not an unprimeable number, because it can be changed into a prime (13086121) 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, 19080 + ... + 19753.

It is an arithmetic number, because the mean of its divisors is an integer number (3281473).

It is a Proth number, since it is equal to 3195 ⋅ 2¹² + 1 and 3195 < 2¹².

Almost surely, 2^13086721 is an apocalyptic number.

It is an amenable number.

13086721 is a deficient number, since it is larger than the sum of its proper divisors (39171).

13086721 is an equidigital number, since it uses as much as digits as its factorization.

13086721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39170.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 13086721 is about 3617.5573250468. The cubic root of 13086721 is about 235.6551568510.

The spelling of 13086721 in words is "thirteen million, eighty-six thousand, seven hundred twenty-one".