243101205509 has 2 divisors, whose sum is σ = 243101205510. Its totient is φ = 243101205508.

The previous prime is 243101205493. The next prime is 243101205517. The reversal of 243101205509 is 905502101342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 153174390625 + 89926814884 = 391375^2 + 299878^2 .

It is a cyclic number.

It is not a de Polignac number, because 243101205509 - 2⁴ = 243101205493 is a prime.

It is a super-2 number, since 2×243101205509² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243101205209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121550602754 + 121550602755.

It is an arithmetic number, because the mean of its divisors is an integer number (121550602755).

Almost surely, 2^243101205509 is an apocalyptic number.

It is an amenable number.

243101205509 is a deficient number, since it is larger than the sum of its proper divisors (1).

243101205509 is an equidigital number, since it uses as much as digits as its factorization.

243101205509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10800, while the sum is 32.

The spelling of 243101205509 in words is "two hundred forty-three billion, one hundred one million, two hundred five thousand, five hundred nine".