1313331221 has 4 divisors (see below), whose sum is σ = 1314175200. Its totient is φ = 1312487244.

The previous prime is 1313331203. The next prime is 1313331263. The reversal of 1313331221 is 1221333131.

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: 1221333131 = 83 ⋅14714857.

It is a cyclic number.

It is not a de Polignac number, because 1313331221 - 2¹⁰ = 1313330197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1313331193 and 1313331202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1313334221) 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, 419651 + ... + 422768.

It is an arithmetic number, because the mean of its divisors is an integer number (328543800).

Almost surely, 2^1313331221 is an apocalyptic number.

It is an amenable number.

1313331221 is a deficient number, since it is larger than the sum of its proper divisors (843979).

1313331221 is an equidigital number, since it uses as much as digits as its factorization.

1313331221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 843978.

The product of its digits is 324, while the sum is 20.

The square root of 1313331221 is about 36239.9119894075. The cubic root of 1313331221 is about 1095.1108694201.

Adding to 1313331221 its reverse (1221333131), we get a palindrome (2534664352).

The spelling of 1313331221 in words is "one billion, three hundred thirteen million, three hundred thirty-one thousand, two hundred twenty-one".