65656140479981 has 2 divisors, whose sum is σ = 65656140479982. Its totient is φ = 65656140479980.

The previous prime is 65656140479957. The next prime is 65656140480019. The reversal of 65656140479981 is 18997404165656.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56016767269225 + 9639373210756 = 7484435^2 + 3104734^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-65656140479981 is a prime.

It is a super-2 number, since 2×65656140479981² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65656140479921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32828070239990 + 32828070239991.

It is an arithmetic number, because the mean of its divisors is an integer number (32828070239991).

Almost surely, 2^{65656140479981} is an apocalyptic number.

It is an amenable number.

65656140479981 is a deficient number, since it is larger than the sum of its proper divisors (1).

65656140479981 is an equidigital number, since it uses as much as digits as its factorization.

65656140479981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 391910400, while the sum is 71.

The spelling of 65656140479981 in words is "sixty-five trillion, six hundred fifty-six billion, one hundred forty million, four hundred seventy-nine thousand, nine hundred eighty-one".