13128681 has 8 divisors (see below), whose sum is σ = 17751744. Its totient is φ = 8629040.

The previous prime is 13128667. The next prime is 13128701. The reversal of 13128681 is 18682131.

13128681 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 13128681 - 2⁵ = 13128649 is a prime.

It is a super-2 number, since 2×13128681² = 344724529599522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (13128581) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30606 + ... + 31031.

It is an arithmetic number, because the mean of its divisors is an integer number (2218968).

Almost surely, 2^13128681 is an apocalyptic number.

It is an amenable number.

13128681 is a deficient number, since it is larger than the sum of its proper divisors (4623063).

13128681 is an equidigital number, since it uses as much as digits as its factorization.

13128681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61711.

The product of its digits is 2304, while the sum is 30.

The square root of 13128681 is about 3623.3521771972. The cubic root of 13128681 is about 235.9067488042.

The spelling of 13128681 in words is "thirteen million, one hundred twenty-eight thousand, six hundred eighty-one".