1242040321 has 4 divisors (see below), whose sum is σ = 1242886144. Its totient is φ = 1241194500.

The previous prime is 1242040259. The next prime is 1242040351. The reversal of 1242040321 is 1230402421.

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 1242040321 - 2⁷ = 1242040193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1242040351) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 420705 + ... + 423646.

It is an arithmetic number, because the mean of its divisors is an integer number (310721536).

Almost surely, 2^1242040321 is an apocalyptic number.

It is an amenable number.

1242040321 is a deficient number, since it is larger than the sum of its proper divisors (845823).

1242040321 is an equidigital number, since it uses as much as digits as its factorization.

1242040321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 845822.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 1242040321 is about 35242.5924273456. The cubic root of 1242040321 is about 1074.9259933909.

Adding to 1242040321 its reverse (1230402421), we get a palindrome (2472442742).

Subtracting from 1242040321 its reverse (1230402421), we obtain a triangular number (11637900 = T₄₈₂₄).

The spelling of 1242040321 in words is "one billion, two hundred forty-two million, forty thousand, three hundred twenty-one".