65381681 has 2 divisors, whose sum is σ = 65381682. Its totient is φ = 65381680.

The previous prime is 65381671. The next prime is 65381683. The reversal of 65381681 is 18618356.

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., 65351056 + 30625 = 8084^2 + 175^2 .

It is a cyclic number.

It is not a de Polignac number, because 65381681 - 2²² = 61187377 is a prime.

It is a super-2 number, since 2×65381681² = 8549528420771522, which contains 22 as substring.

Together with 65381683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (65381683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32690840 + 32690841.

It is an arithmetic number, because the mean of its divisors is an integer number (32690841).

Almost surely, 2^65381681 is an apocalyptic number.

It is an amenable number.

65381681 is a deficient number, since it is larger than the sum of its proper divisors (1).

65381681 is an equidigital number, since it uses as much as digits as its factorization.

65381681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34560, while the sum is 38.

The square root of 65381681 is about 8085.8939518151. The cubic root of 65381681 is about 402.8580325716.

The spelling of 65381681 in words is "sixty-five million, three hundred eighty-one thousand, six hundred eighty-one".