521420 has 36 divisors (see below), whose sum is σ = 1170624. Its totient is φ = 194880.

The previous prime is 521401. The next prime is 521429. The reversal of 521420 is 24125.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 521395 and 521404.

It is not an unprimeable number, because it can be changed into a prime (521429) 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, 16805 + ... + 16835.

2⁵²¹⁴²⁰ 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 521420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (585312).

521420 is an abundant number, since it is smaller than the sum of its proper divisors (649204).

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

521420 is a wasteful number, since it uses less digits than its factorization.

521420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98 (or 67 counting only the distinct ones).

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

The square root of 521420 is about 722.0941766833. The cubic root of 521420 is about 80.4876464718.

Adding to 521420 its reverse (24125), we get a palindrome (545545).

The spelling of 521420 in words is "five hundred twenty-one thousand, four hundred twenty".