517421309 has 2 divisors, whose sum is σ = 517421310. Its totient is φ = 517421308.

The previous prime is 517421287. The next prime is 517421321. The reversal of 517421309 is 903124715.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 298529284 + 218892025 = 17278^2 + 14795^2 .

It is a cyclic number.

It is not a de Polignac number, because 517421309 - 2²⁰ = 516372733 is a prime.

It is a super-2 number, since 2×517421309² = 535449622014546962, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (517421339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 258710654 + 258710655.

It is an arithmetic number, because the mean of its divisors is an integer number (258710655).

Almost surely, 2^517421309 is an apocalyptic number.

It is an amenable number.

517421309 is a deficient number, since it is larger than the sum of its proper divisors (1).

517421309 is an equidigital number, since it uses as much as digits as its factorization.

517421309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 517421309 is about 22746.8966894388. The cubic root of 517421309 is about 802.8136907660.

The spelling of 517421309 in words is "five hundred seventeen million, four hundred twenty-one thousand, three hundred nine".