81762763790689 has 2 divisors, whose sum is σ = 81762763790690. Its totient is φ = 81762763790688.

The previous prime is 81762763790621. The next prime is 81762763790777. The reversal of 81762763790689 is 98609736726718.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56699273531664 + 25063490259025 = 7529892^2 + 5006345^2 .

It is a cyclic number.

It is not a de Polignac number, because 81762763790689 - 2¹⁷ = 81762763659617 is a prime.

It is not a weakly prime, because it can be changed into another prime (81762763796689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40881381895344 + 40881381895345.

It is an arithmetic number, because the mean of its divisors is an integer number (40881381895345).

Almost surely, 2^{81762763790689} is an apocalyptic number.

It is an amenable number.

81762763790689 is a deficient number, since it is larger than the sum of its proper divisors (1).

81762763790689 is an equidigital number, since it uses as much as digits as its factorization.

81762763790689 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304433152, while the sum is 79.

The spelling of 81762763790689 in words is "eighty-one trillion, seven hundred sixty-two billion, seven hundred sixty-three million, seven hundred ninety thousand, six hundred eighty-nine".