521742673 has 2 divisors, whose sum is σ = 521742674. Its totient is φ = 521742672.

The previous prime is 521742659. The next prime is 521742677. The reversal of 521742673 is 376247125.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 461089729 + 60652944 = 21473^2 + 7788^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-521742673 is a prime.

It is not a weakly prime, because it can be changed into another prime (521742677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260871336 + 260871337.

It is an arithmetic number, because the mean of its divisors is an integer number (260871337).

Almost surely, 2^521742673 is an apocalyptic number.

It is an amenable number.

521742673 is a deficient number, since it is larger than the sum of its proper divisors (1).

521742673 is an equidigital number, since it uses as much as digits as its factorization.

521742673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 70560, while the sum is 37.

The square root of 521742673 is about 22841.6871749878. The cubic root of 521742673 is about 805.0424590853.

Adding to 521742673 its reverse (376247125), we get a palindrome (897989798).

The spelling of 521742673 in words is "five hundred twenty-one million, seven hundred forty-two thousand, six hundred seventy-three".