521109 has 6 divisors (see below), whose sum is σ = 752726. Its totient is φ = 347400.

The previous prime is 521107. The next prime is 521119. The reversal of 521109 is 901125.

It can be written as a sum of positive squares in only one way, i.e., 378225 + 142884 = 615^2 + 378^2 .

It is not a de Polignac number, because 521109 - 2¹ = 521107 is a prime.

It is a Duffinian number.

521109 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 521091 and 521100.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 521109.

It is not an unprimeable number, because it can be changed into a prime (521107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 28942 + ... + 28959.

2⁵²¹¹⁰⁹ is an apocalyptic number.

It is an amenable number.

521109 is a deficient number, since it is larger than the sum of its proper divisors (231617).

521109 is a wasteful number, since it uses less digits than its factorization.

521109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57907 (or 57904 counting only the distinct ones).

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

The square root of 521109 is about 721.8787986913. The cubic root of 521109 is about 80.4716410530.

It can be divided in two parts, 521 and 109, that added together give a triangular number (630 = T₃₅).

The spelling of 521109 in words is "five hundred twenty-one thousand, one hundred nine".