65666777519977 has 2 divisors, whose sum is σ = 65666777519978. Its totient is φ = 65666777519976.

The previous prime is 65666777519969. The next prime is 65666777520053. The reversal of 65666777519977 is 77991577766656.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56060844289641 + 9605933230336 = 7487379^2 + 3099344^2 .

It is a cyclic number.

It is not a de Polignac number, because 65666777519977 - 2³ = 65666777519969 is a prime.

It is not a weakly prime, because it can be changed into another prime (65666777519177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32833388759988 + 32833388759989.

It is an arithmetic number, because the mean of its divisors is an integer number (32833388759989).

Almost surely, 2^{65666777519977} is an apocalyptic number.

It is an amenable number.

65666777519977 is a deficient number, since it is larger than the sum of its proper divisors (1).

65666777519977 is an equidigital number, since it uses as much as digits as its factorization.

65666777519977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 44108290800, while the sum is 88.

The spelling of 65666777519977 in words is "sixty-five trillion, six hundred sixty-six billion, seven hundred seventy-seven million, five hundred nineteen thousand, nine hundred seventy-seven".