509121 has 6 divisors (see below), whose sum is σ = 735410. Its totient is φ = 339408.

The previous prime is 509101. The next prime is 509123. The reversal of 509121 is 121905.

It can be written as a sum of positive squares in only one way, i.e., 505521 + 3600 = 711^2 + 60^2 .

It is not a de Polignac number, because 509121 - 2¹⁰ = 508097 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 509094 and 509103.

It is not an unprimeable number, because it can be changed into a prime (509123) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 28276 + ... + 28293.

2⁵⁰⁹¹²¹ is an apocalyptic number.

It is an amenable number.

509121 is a deficient number, since it is larger than the sum of its proper divisors (226289).

509121 is a wasteful number, since it uses less digits than its factorization.

509121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56575 (or 56572 counting only the distinct ones).

The product of its (nonzero) digits is 90, while the sum is 18.

The square root of 509121 is about 713.5271543536. The cubic root of 509121 is about 79.8497701473.

It can be divided in two parts, 509 and 121, that added together give a triangular number (630 = T₃₅).

The spelling of 509121 in words is "five hundred nine thousand, one hundred twenty-one".