243007640021 has 2 divisors, whose sum is σ = 243007640022. Its totient is φ = 243007640020.

The previous prime is 243007640011. The next prime is 243007640027. The reversal of 243007640021 is 120046700342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 232696252996 + 10311387025 = 482386^2 + 101545^2 .

It is a cyclic number.

It is not a de Polignac number, because 243007640021 - 2²⁶ = 242940531157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243007640027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121503820010 + 121503820011.

It is an arithmetic number, because the mean of its divisors is an integer number (121503820011).

Almost surely, 2^243007640021 is an apocalyptic number.

It is an amenable number.

243007640021 is a deficient number, since it is larger than the sum of its proper divisors (1).

243007640021 is an equidigital number, since it uses as much as digits as its factorization.

243007640021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 29.

The spelling of 243007640021 in words is "two hundred forty-three billion, seven million, six hundred forty thousand, twenty-one".