75085781 has 2 divisors, whose sum is σ = 75085782. Its totient is φ = 75085780.

The previous prime is 75085763. The next prime is 75085793. The reversal of 75085781 is 18758057.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53787556 + 21298225 = 7334^2 + 4615^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-75085781 is a prime.

It is a super-2 number, since 2×75085781² = 11275749016759922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (75085741) 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, 37542890 + 37542891.

It is an arithmetic number, because the mean of its divisors is an integer number (37542891).

Almost surely, 2^75085781 is an apocalyptic number.

It is an amenable number.

75085781 is a deficient number, since it is larger than the sum of its proper divisors (1).

75085781 is an equidigital number, since it uses as much as digits as its factorization.

75085781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 78400, while the sum is 41.

The square root of 75085781 is about 8665.2051908769. The cubic root of 75085781 is about 421.8770502763.

The spelling of 75085781 in words is "seventy-five million, eighty-five thousand, seven hundred eighty-one".