1321243442 has 4 divisors (see below), whose sum is σ = 1981865166. Its totient is φ = 660621720.

The previous prime is 1321243433. The next prime is 1321243447. The reversal of 1321243442 is 2443421231.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2443421231 = 31013 ⋅78787.

It can be written as a sum of positive squares in only one way, i.e., 1319941561 + 1301881 = 36331^2 + 1141^2 .

It is not an unprimeable number, because it can be changed into a prime (1321243447) 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 as a sum of consecutive naturals, namely, 330310859 + ... + 330310862.

Almost surely, 2^1321243442 is an apocalyptic number.

1321243442 is a deficient number, since it is larger than the sum of its proper divisors (660621724).

1321243442 is an equidigital number, since it uses as much as digits as its factorization.

1321243442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 660621723.

The product of its digits is 4608, while the sum is 26.

The square root of 1321243442 is about 36348.9125284375. The cubic root of 1321243442 is about 1097.3056487923.

Adding to 1321243442 its reverse (2443421231), we get a palindrome (3764664673).

The spelling of 1321243442 in words is "one billion, three hundred twenty-one million, two hundred forty-three thousand, four hundred forty-two".