520318177661 has 2 divisors, whose sum is σ = 520318177662. Its totient is φ = 520318177660.

The previous prime is 520318177609. The next prime is 520318177663. The reversal of 520318177661 is 166771813025.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 480200491225 + 40117686436 = 692965^2 + 200294^2 .

It is a cyclic number.

It is not a de Polignac number, because 520318177661 - 2¹⁸ = 520317915517 is a prime.

Together with 520318177663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (520318177663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260159088830 + 260159088831.

It is an arithmetic number, because the mean of its divisors is an integer number (260159088831).

Almost surely, 2^520318177661 is an apocalyptic number.

It is an amenable number.

520318177661 is a deficient number, since it is larger than the sum of its proper divisors (1).

520318177661 is an equidigital number, since it uses as much as digits as its factorization.

520318177661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 423360, while the sum is 47.

The spelling of 520318177661 in words is "five hundred twenty billion, three hundred eighteen million, one hundred seventy-seven thousand, six hundred sixty-one".