65785425581 has 2 divisors, whose sum is σ = 65785425582. Its totient is φ = 65785425580.

The previous prime is 65785425553. The next prime is 65785425619. The reversal of 65785425581 is 18552458756.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65674312900 + 111112681 = 256270^2 + 10541^2 .

It is a cyclic number.

It is not a de Polignac number, because 65785425581 - 2¹⁰ = 65785424557 is a prime.

It is a super-2 number, since 2×65785425581² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65785425481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32892712790 + 32892712791.

It is an arithmetic number, because the mean of its divisors is an integer number (32892712791).

Almost surely, 2^65785425581 is an apocalyptic number.

It is an amenable number.

65785425581 is a deficient number, since it is larger than the sum of its proper divisors (1).

65785425581 is an equidigital number, since it uses as much as digits as its factorization.

65785425581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13440000, while the sum is 56.

The spelling of 65785425581 in words is "sixty-five billion, seven hundred eighty-five million, four hundred twenty-five thousand, five hundred eighty-one".