520667681 has 2 divisors, whose sum is σ = 520667682. Its totient is φ = 520667680.

The previous prime is 520667669. The next prime is 520667683. The reversal of 520667681 is 186766025.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 369254656 + 151413025 = 19216^2 + 12305^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-520667681 is a prime.

It is a super-2 number, since 2×520667681² = 542189668075835522, which contains 22 as substring.

Together with 520667683, 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 (520667683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260333840 + 260333841.

It is an arithmetic number, because the mean of its divisors is an integer number (260333841).

Almost surely, 2^520667681 is an apocalyptic number.

It is an amenable number.

520667681 is a deficient number, since it is larger than the sum of its proper divisors (1).

520667681 is an equidigital number, since it uses as much as digits as its factorization.

520667681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120960, while the sum is 41.

The square root of 520667681 is about 22818.1436799754. The cubic root of 520667681 is about 804.4891791562.

The spelling of 520667681 in words is "five hundred twenty million, six hundred sixty-seven thousand, six hundred eighty-one".