521729 has 8 divisors (see below), whose sum is σ = 571200. Its totient is φ = 473616.

The previous prime is 521723. The next prime is 521743. The reversal of 521729 is 927125.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 521729 - 2¹⁶ = 456193 is a prime.

It is a super-2 number, since 2×521729² = 544402298882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 521698 and 521707.

It is not an unprimeable number, because it can be changed into a prime (521723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 572 + ... + 1170.

It is an arithmetic number, because the mean of its divisors is an integer number (71400).

2⁵²¹⁷²⁹ is an apocalyptic number.

It is an amenable number.

521729 is a deficient number, since it is larger than the sum of its proper divisors (49471).

521729 is a wasteful number, since it uses less digits than its factorization.

521729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 679.

The product of its digits is 1260, while the sum is 26.

The square root of 521729 is about 722.3081060046. The cubic root of 521729 is about 80.5035426601.

The spelling of 521729 in words is "five hundred twenty-one thousand, seven hundred twenty-nine".