13031321 has 4 divisors (see below), whose sum is σ = 13717200. Its totient is φ = 12345444.

The previous prime is 13031309. The next prime is 13031329. The reversal of 13031321 is 12313031.

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: 12313031 = 127 ⋅96953.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13031321 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13031296 and 13031305.

It is not an unprimeable number, because it can be changed into a prime (13031329) 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, 342911 + ... + 342948.

It is an arithmetic number, because the mean of its divisors is an integer number (3429300).

Almost surely, 2^13031321 is an apocalyptic number.

It is an amenable number.

13031321 is a deficient number, since it is larger than the sum of its proper divisors (685879).

13031321 is an equidigital number, since it uses as much as digits as its factorization.

13031321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 685878.

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

The square root of 13031321 is about 3609.8921036507. The cubic root of 13031321 is about 235.3221536115.

Adding to 13031321 its reverse (12313031), we get a palindrome (25344352).

The spelling of 13031321 in words is "thirteen million, thirty-one thousand, three hundred twenty-one".