516471721 has 2 divisors, whose sum is σ = 516471722. Its totient is φ = 516471720.

The previous prime is 516471719. The next prime is 516471727. The reversal of 516471721 is 127174615.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 457489321 + 58982400 = 21389^2 + 7680^2 .

It is a cyclic number.

It is not a de Polignac number, because 516471721 - 2¹ = 516471719 is a prime.

Together with 516471719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (516471727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 258235860 + 258235861.

It is an arithmetic number, because the mean of its divisors is an integer number (258235861).

Almost surely, 2^516471721 is an apocalyptic number.

It is an amenable number.

516471721 is a deficient number, since it is larger than the sum of its proper divisors (1).

516471721 is an equidigital number, since it uses as much as digits as its factorization.

516471721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11760, while the sum is 34.

The square root of 516471721 is about 22726.0141907903. The cubic root of 516471721 is about 802.3222736377.

The spelling of 516471721 in words is "five hundred sixteen million, four hundred seventy-one thousand, seven hundred twenty-one".