521240 has 32 divisors (see below), whose sum is σ = 1194480. Its totient is φ = 204672.

The previous prime is 521231. The next prime is 521243. The reversal of 521240 is 42125.

521240 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×521240² = 543382275200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521243) by changing a digit.

521240 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3242 + ... + 3398.

2⁵²¹²⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 521240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (597240).

521240 is an abundant number, since it is smaller than the sum of its proper divisors (673240).

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

521240 is a wasteful number, since it uses less digits than its factorization.

521240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251 (or 247 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 14.

The square root of 521240 is about 721.9695284429. The cubic root of 521240 is about 80.4783836614.

Adding to 521240 its reverse (42125), we get a palindrome (563365).

The spelling of 521240 in words is "five hundred twenty-one thousand, two hundred forty".