1312321221 has 12 divisors (see below), whose sum is σ = 1905103200. Its totient is φ = 870483240.

The previous prime is 1312321207. The next prime is 1312321259. The reversal of 1312321221 is 1221232131.

1312321221 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1312321221 - 2¹³ = 1312313029 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1312321194 and 1312321203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1312321321) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 364575 + ... + 368156.

It is an arithmetic number, because the mean of its divisors is an integer number (158758600).

Almost surely, 2^1312321221 is an apocalyptic number.

It is an amenable number.

1312321221 is a deficient number, since it is larger than the sum of its proper divisors (592781979).

1312321221 is a wasteful number, since it uses less digits than its factorization.

1312321221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 732936 (or 732933 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 1312321221 is about 36225.9743968330. The cubic root of 1312321221 is about 1094.8300705844.

Adding to 1312321221 its reverse (1221232131), we get a palindrome (2533553352).

The spelling of 1312321221 in words is "one billion, three hundred twelve million, three hundred twenty-one thousand, two hundred twenty-one".