521801 has 12 divisors (see below), whose sum is σ = 634752. Its totient is φ = 426888.

The previous prime is 521791. The next prime is 521809. The reversal of 521801 is 108125.

It is not a de Polignac number, because 521801 - 2¹⁸ = 259657 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 521801.

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 521801.

It is not an unprimeable number, because it can be changed into a prime (521809) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 896 + ... + 1358.

It is an arithmetic number, because the mean of its divisors is an integer number (52896).

2⁵²¹⁸⁰¹ is an apocalyptic number.

It is an amenable number.

521801 is a deficient number, since it is larger than the sum of its proper divisors (112951).

521801 is a wasteful number, since it uses less digits than its factorization.

521801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500 (or 493 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 17.

The square root of 521801 is about 722.3579445123. The cubic root of 521801 is about 80.5072457246.

Adding to 521801 its reverse (108125), we get a palindrome (629926).

The spelling of 521801 in words is "five hundred twenty-one thousand, eight hundred one".