65781697 has 2 divisors, whose sum is σ = 65781698. Its totient is φ = 65781696.

The previous prime is 65781691. The next prime is 65781719. The reversal of 65781697 is 79618756.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54228496 + 11553201 = 7364^2 + 3399^2 .

It is a cyclic number.

It is not a de Polignac number, because 65781697 - 2¹⁵ = 65748929 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 65781697.

It is not a weakly prime, because it can be changed into another prime (65781691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32890848 + 32890849.

It is an arithmetic number, because the mean of its divisors is an integer number (32890849).

Almost surely, 2^65781697 is an apocalyptic number.

It is an amenable number.

65781697 is a deficient number, since it is larger than the sum of its proper divisors (1).

65781697 is an equidigital number, since it uses as much as digits as its factorization.

65781697 is an evil number, because the sum of its binary digits is even.

The product of its digits is 635040, while the sum is 49.

The square root of 65781697 is about 8110.5916553603. The cubic root of 65781697 is about 403.6779468657.

The spelling of 65781697 in words is "sixty-five million, seven hundred eighty-one thousand, six hundred ninety-seven".