517421 has 4 divisors (see below), whose sum is σ = 534144. Its totient is φ = 500700.

The previous prime is 517417. The next prime is 517457. The reversal of 517421 is 124715.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 124715 = 5 ⋅24943.

It is a cyclic number.

It is not a de Polignac number, because 517421 - 2² = 517417 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 517393 and 517402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (517411) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8315 + ... + 8376.

It is an arithmetic number, because the mean of its divisors is an integer number (133536).

2⁵¹⁷⁴²¹ is an apocalyptic number.

It is an amenable number.

517421 is a deficient number, since it is larger than the sum of its proper divisors (16723).

517421 is a wasteful number, since it uses less digits than its factorization.

517421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16722.

The product of its digits is 280, while the sum is 20.

The square root of 517421 is about 719.3198176055. The cubic root of 517421 is about 80.2813530955.

The spelling of 517421 in words is "five hundred seventeen thousand, four hundred twenty-one".