1212031321 has 4 divisors (see below), whose sum is σ = 1226634192. Its totient is φ = 1197428452.

The previous prime is 1212031319. The next prime is 1212031343. The reversal of 1212031321 is 1231302121.

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: 1231302121 = 7 ⋅175900303.

It is a cyclic number.

It is not a de Polignac number, because 1212031321 - 2¹ = 1212031319 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1212031295 and 1212031304.

It is not an unprimeable number, because it can be changed into a prime (1212031361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7301311 + ... + 7301476.

It is an arithmetic number, because the mean of its divisors is an integer number (306658548).

Almost surely, 2^1212031321 is an apocalyptic number.

It is an amenable number.

1212031321 is a deficient number, since it is larger than the sum of its proper divisors (14602871).

1212031321 is an equidigital number, since it uses as much as digits as its factorization.

1212031321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14602870.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 1212031321 is about 34814.2402042612. The cubic root of 1212031321 is about 1066.1982064764.

Adding to 1212031321 its reverse (1231302121), we get a palindrome (2443333442).

The spelling of 1212031321 in words is "one billion, two hundred twelve million, thirty-one thousand, three hundred twenty-one".