1321440243 has 16 divisors (see below), whose sum is σ = 1873944576. Its totient is φ = 825413760.

The previous prime is 1321440223. The next prime is 1321440293. The reversal of 1321440243 is 3420441231.

It is not a de Polignac number, because 1321440243 - 2⁶ = 1321440179 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1321440223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46723 + ... + 69468.

It is an arithmetic number, because the mean of its divisors is an integer number (117121536).

Almost surely, 2^1321440243 is an apocalyptic number.

1321440243 is a deficient number, since it is larger than the sum of its proper divisors (552504333).

1321440243 is a wasteful number, since it uses less digits than its factorization.

1321440243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116434.

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 1321440243 is about 36351.6195375117. The cubic root of 1321440243 is about 1097.3601278083.

Adding to 1321440243 its reverse (3420441231), we get a palindrome (4741881474).

The spelling of 1321440243 in words is "one billion, three hundred twenty-one million, four hundred forty thousand, two hundred forty-three".