509951 has 4 divisors (see below), whose sum is σ = 549192. Its totient is φ = 470712.

The previous prime is 509947. The next prime is 509959. The reversal of 509951 is 159905.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 159905 = 5 ⋅31981.

It is a cyclic number.

It is not a de Polignac number, because 509951 - 2² = 509947 is a prime.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (509959) 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, 19601 + ... + 19626.

It is an arithmetic number, because the mean of its divisors is an integer number (137298).

2⁵⁰⁹⁹⁵¹ is an apocalyptic number.

509951 is a deficient number, since it is larger than the sum of its proper divisors (39241).

509951 is a wasteful number, since it uses less digits than its factorization.

509951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39240.

The product of its (nonzero) digits is 2025, while the sum is 29.

The square root of 509951 is about 714.1085351681. The cubic root of 509951 is about 79.8931385715.

It can be divided in two parts, 50 and 9951, that added together give a palindrome (10001).

The spelling of 509951 in words is "five hundred nine thousand, nine hundred fifty-one".