508721 has 4 divisors (see below), whose sum is σ = 511344. Its totient is φ = 506100.

The previous prime is 508709. The next prime is 508727. The reversal of 508721 is 127805.

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: 127805 = 5 ⋅25561.

It is a cyclic number.

It is not a de Polignac number, because 508721 - 2¹⁰ = 507697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (508727) 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, 995 + ... + 1416.

It is an arithmetic number, because the mean of its divisors is an integer number (127836).

2⁵⁰⁸⁷²¹ is an apocalyptic number.

It is an amenable number.

508721 is a deficient number, since it is larger than the sum of its proper divisors (2623).

508721 is a wasteful number, since it uses less digits than its factorization.

508721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2622.

The product of its (nonzero) digits is 560, while the sum is 23.

The square root of 508721 is about 713.2468016052. The cubic root of 508721 is about 79.8288528693.

The spelling of 508721 in words is "five hundred eight thousand, seven hundred twenty-one".