1243142321 has 4 divisors (see below), whose sum is σ = 1261696752. Its totient is φ = 1224587892.

The previous prime is 1243142309. The next prime is 1243142389. The reversal of 1243142321 is 1232413421.

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.

It is a cyclic number.

It is not a de Polignac number, because 1243142321 - 2¹⁰ = 1243141297 is a prime.

It is a super-2 number, since 2×1243142321² = 3090805660522534082, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1243141321) 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, 9277115 + ... + 9277248.

It is an arithmetic number, because the mean of its divisors is an integer number (315424188).

Almost surely, 2^1243142321 is an apocalyptic number.

It is an amenable number.

1243142321 is a deficient number, since it is larger than the sum of its proper divisors (18554431).

1243142321 is an equidigital number, since it uses as much as digits as its factorization.

1243142321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18554430.

The product of its digits is 1152, while the sum is 23.

The square root of 1243142321 is about 35258.2234521253. The cubic root of 1243142321 is about 1075.2438086989.

Adding to 1243142321 its reverse (1232413421), we get a palindrome (2475555742).

The spelling of 1243142321 in words is "one billion, two hundred forty-three million, one hundred forty-two thousand, three hundred twenty-one".