521340 has 24 divisors (see below), whose sum is σ = 1459920. Its totient is φ = 139008.

The previous prime is 521329. The next prime is 521357. The reversal of 521340 is 43125.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

521340 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 7 ways as a sum of consecutive naturals, for example, 4285 + ... + 4404.

It is an arithmetic number, because the mean of its divisors is an integer number (60830).

2⁵²¹³⁴⁰ is an apocalyptic number.

It is an amenable number.

521340 is an abundant number, since it is smaller than the sum of its proper divisors (938580).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

521340 is a wasteful number, since it uses less digits than its factorization.

521340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8701 (or 8699 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 521340 is about 722.0387801220. The cubic root of 521340 is about 80.4835299304.

Adding to 521340 its reverse (43125), we get a palindrome (564465).

It can be divided in two parts, 5213 and 40, that added together give a triangular number (5253 = T₁₀₂).

The spelling of 521340 in words is "five hundred twenty-one thousand, three hundred forty".