13031221 has 8 divisors (see below), whose sum is σ = 14926464. Its totient is φ = 11144400.

The previous prime is 13031201. The next prime is 13031233. The reversal of 13031221 is 12213031.

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 13031221 - 2⁵ = 13031189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13031201) 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, 1671 + ... + 5371.

It is an arithmetic number, because the mean of its divisors is an integer number (1865808).

Almost surely, 2^13031221 is an apocalyptic number.

It is an amenable number.

13031221 is a deficient number, since it is larger than the sum of its proper divisors (1895243).

13031221 is an equidigital number, since it uses as much as digits as its factorization.

13031221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4211.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 13031221 is about 3609.8782527947. The cubic root of 13031221 is about 235.3215516701.

Adding to 13031221 its reverse (12213031), we get a palindrome (25244252).

The spelling of 13031221 in words is "thirteen million, thirty-one thousand, two hundred twenty-one".