13087681 has 4 divisors (see below), whose sum is σ = 13217364. Its totient is φ = 12958000.

The previous prime is 13087649. The next prime is 13087687. The reversal of 13087681 is 18678031.

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 5475600 + 7612081 = 2340^2 + 2759^2 .

It is a cyclic number.

It is not a de Polignac number, because 13087681 - 2⁵ = 13087649 is a prime.

It is a super-2 number, since 2×13087681² = 342574787915522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13087687) by changing a digit.

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, 64690 + ... + 64891.

It is an arithmetic number, because the mean of its divisors is an integer number (3304341).

Almost surely, 2^13087681 is an apocalyptic number.

It is an amenable number.

13087681 is a deficient number, since it is larger than the sum of its proper divisors (129683).

13087681 is a wasteful number, since it uses less digits than its factorization.

13087681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129682.

The product of its (nonzero) digits is 8064, while the sum is 34.

The square root of 13087681 is about 3617.6900088316. The cubic root of 13087681 is about 235.6609190130.

The spelling of 13087681 in words is "thirteen million, eighty-seven thousand, six hundred eighty-one".