1243405321 has 16 divisors (see below), whose sum is σ = 1282635648. Its totient is φ = 1204940800.

The previous prime is 1243405309. The next prime is 1243405327. The reversal of 1243405321 is 1235043421.

It is a cyclic number.

It is not a de Polignac number, because 1243405321 - 2⁹ = 1243404809 is a prime.

It is a super-2 number, since 2×1243405321² = 3092113584582226082, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1243405327) 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 15 ways as a sum of consecutive naturals, for example, 1514091 + ... + 1514911.

It is an arithmetic number, because the mean of its divisors is an integer number (80164728).

Almost surely, 2^1243405321 is an apocalyptic number.

It is an amenable number.

1243405321 is a deficient number, since it is larger than the sum of its proper divisors (39230327).

1243405321 is an equidigital number, since it uses as much as digits as its factorization.

1243405321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1232.

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 1243405321 is about 35261.9528812572. The cubic root of 1243405321 is about 1075.3196297793.

Adding to 1243405321 its reverse (1235043421), we get a palindrome (2478448742).

The spelling of 1243405321 in words is "one billion, two hundred forty-three million, four hundred five thousand, three hundred twenty-one".