240256040021 has 2 divisors, whose sum is σ = 240256040022. Its totient is φ = 240256040020.

The previous prime is 240256039987. The next prime is 240256040077. The reversal of 240256040021 is 120040652042.

240256040021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 235114432996 + 5141607025 = 484886^2 + 71705^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-240256040021 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (240256042021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 120128020010 + 120128020011.

It is an arithmetic number, because the mean of its divisors is an integer number (120128020011).

Almost surely, 2^240256040021 is an apocalyptic number.

It is an amenable number.

240256040021 is a deficient number, since it is larger than the sum of its proper divisors (1).

240256040021 is an equidigital number, since it uses as much as digits as its factorization.

240256040021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3840, while the sum is 26.

Adding to 240256040021 its reverse (120040652042), we get a palindrome (360296692063).

The spelling of 240256040021 in words is "two hundred forty billion, two hundred fifty-six million, forty thousand, twenty-one".