13136721 has 16 divisors (see below), whose sum is σ = 18985344. Its totient is φ = 8031744.

The previous prime is 13136713. The next prime is 13136737. The reversal of 13136721 is 12763131.

It is not a de Polignac number, because 13136721 - 2³ = 13136713 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13136691 and 13136700.

It is not an unprimeable number, because it can be changed into a prime (13136701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5505 + ... + 7521.

It is an arithmetic number, because the mean of its divisors is an integer number (1186584).

Almost surely, 2^13136721 is an apocalyptic number.

It is an amenable number.

13136721 is a deficient number, since it is larger than the sum of its proper divisors (5848623).

13136721 is a wasteful number, since it uses less digits than its factorization.

13136721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2200.

The product of its digits is 756, while the sum is 24.

The square root of 13136721 is about 3624.4614772404. The cubic root of 13136721 is about 235.9548953828.

Adding to 13136721 its reverse (12763131), we get a palindrome (25899852).

The spelling of 13136721 in words is "thirteen million, one hundred thirty-six thousand, seven hundred twenty-one".