13131681 has 4 divisors (see below), whose sum is σ = 17508912. Its totient is φ = 8754452.

The previous prime is 13131661. The next prime is 13131719. The reversal of 13131681 is 18613131.

13131681 is digitally balanced in base 2, base 3 and base 4, because in such bases it contains all the possibile digits an equal number of times.

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: 18613131 = 3 ⋅6204377.

It is a cyclic number.

It is not a de Polignac number, because 13131681 - 2⁵ = 13131649 is a prime.

It is a super-2 number, since 2×13131681² = 344882091771522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (13131661) 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, 2188611 + ... + 2188616.

It is an arithmetic number, because the mean of its divisors is an integer number (4377228).

Almost surely, 2^13131681 is an apocalyptic number.

It is an amenable number.

13131681 is a deficient number, since it is larger than the sum of its proper divisors (4377231).

13131681 is an equidigital number, since it uses as much as digits as its factorization.

13131681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4377230.

The product of its digits is 432, while the sum is 24.

The square root of 13131681 is about 3623.7661348382. The cubic root of 13131681 is about 235.9247162437.

The spelling of 13131681 in words is "thirteen million, one hundred thirty-one thousand, six hundred eighty-one".