13691231 has 4 divisors (see below), whose sum is σ = 13711464. Its totient is φ = 13671000.

The previous prime is 13691213. The next prime is 13691269. The reversal of 13691231 is 13219631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13219631 = 53 ⋅249427.

It is a cyclic number.

It is not a de Polignac number, because 13691231 - 2¹⁴ = 13674847 is a prime.

It is a super-2 number, since 2×13691231² = 374899612590722, which contains 22 as substring.

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 13691231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13691281) 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, 9065 + ... + 10466.

It is an arithmetic number, because the mean of its divisors is an integer number (3427866).

Almost surely, 2^13691231 is an apocalyptic number.

13691231 is a deficient number, since it is larger than the sum of its proper divisors (20233).

13691231 is an equidigital number, since it uses as much as digits as its factorization.

13691231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20232.

The product of its digits is 972, while the sum is 26.

The square root of 13691231 is about 3700.1663476120. The cubic root of 13691231 is about 239.2291878996.

The spelling of 13691231 in words is "thirteen million, six hundred ninety-one thousand, two hundred thirty-one".