521003420 has 144 divisors (see below), whose sum is σ = 1353354240. Its totient is φ = 164975616.

The previous prime is 521003411. The next prime is 521003443. The reversal of 521003420 is 24300125.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3196259 + ... + 3196421.

Almost surely, 2^521003420 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 521003420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (676677120).

521003420 is an abundant number, since it is smaller than the sum of its proper divisors (832350820).

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

521003420 is a wasteful number, since it uses less digits than its factorization.

521003420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292 (or 273 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 521003420 is about 22825.4993373639. The cubic root of 521003420 is about 804.6620599705.

Adding to 521003420 its reverse (24300125), we get a palindrome (545303545).

The spelling of 521003420 in words is "five hundred twenty-one million, three thousand, four hundred twenty".