85781248041509 has 2 divisors, whose sum is σ = 85781248041510. Its totient is φ = 85781248041508.

The previous prime is 85781248041421. The next prime is 85781248041613. The reversal of 85781248041509 is 90514084218758.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84956960184100 + 824287857409 = 9217210^2 + 907903^2 .

It is a cyclic number.

It is not a de Polignac number, because 85781248041509 - 2²⁴ = 85781231264293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85781248041109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42890624020754 + 42890624020755.

It is an arithmetic number, because the mean of its divisors is an integer number (42890624020755).

Almost surely, 2^{85781248041509} is an apocalyptic number.

It is an amenable number.

85781248041509 is a deficient number, since it is larger than the sum of its proper divisors (1).

85781248041509 is an equidigital number, since it uses as much as digits as its factorization.

85781248041509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25804800, while the sum is 62.

The spelling of 85781248041509 in words is "eighty-five trillion, seven hundred eighty-one billion, two hundred forty-eight million, forty-one thousand, five hundred nine".