13031231 has 4 divisors (see below), whose sum is σ = 13797792. Its totient is φ = 12264672.

The previous prime is 13031201. The next prime is 13031233. The reversal of 13031231 is 13213031.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13031231 is a prime.

It is a super-2 number, since 2×13031231² = 339625962750722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13031233) 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, 383255 + ... + 383288.

It is an arithmetic number, because the mean of its divisors is an integer number (3449448).

Almost surely, 2^13031231 is an apocalyptic number.

13031231 is a deficient number, since it is larger than the sum of its proper divisors (766561).

13031231 is an equidigital number, since it uses as much as digits as its factorization.

13031231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 766560.

The product of its (nonzero) digits is 54, while the sum is 14.

The square root of 13031231 is about 3609.8796378827. The cubic root of 13031231 is about 235.3216118644.

Adding to 13031231 its reverse (13213031), we get a palindrome (26244262).

The spelling of 13031231 in words is "thirteen million, thirty-one thousand, two hundred thirty-one".