71835781 has 2 divisors, whose sum is σ = 71835782. Its totient is φ = 71835780.

The previous prime is 71835769. The next prime is 71835791. The reversal of 71835781 is 18753817.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58767556 + 13068225 = 7666^2 + 3615^2 .

It is a cyclic number.

It is not a de Polignac number, because 71835781 - 2⁵ = 71835749 is a prime.

It is a super-2 number, since 2×71835781² = 10320758863759922, 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 (71835791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35917890 + 35917891.

It is an arithmetic number, because the mean of its divisors is an integer number (35917891).

Almost surely, 2^71835781 is an apocalyptic number.

It is an amenable number.

71835781 is a deficient number, since it is larger than the sum of its proper divisors (1).

71835781 is an equidigital number, since it uses as much as digits as its factorization.

71835781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 47040, while the sum is 40.

The square root of 71835781 is about 8475.5991528623. The cubic root of 71835781 is about 415.7002374659.

The spelling of 71835781 in words is "seventy-one million, eight hundred thirty-five thousand, seven hundred eighty-one".