521305020 has 36 divisors (see below), whose sum is σ = 1581292440. Its totient is φ = 139014624.

The previous prime is 521305009. The next prime is 521305049. The reversal of 521305020 is 20503125.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 521304984 and 521305002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1447890 + ... + 1448249.

It is an arithmetic number, because the mean of its divisors is an integer number (43924790).

Almost surely, 2^521305020 is an apocalyptic number.

It is an amenable number.

521305020 is an abundant number, since it is smaller than the sum of its proper divisors (1059987420).

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

521305020 is a wasteful number, since it uses less digits than its factorization.

521305020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2896154 (or 2896149 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 18.

The square root of 521305020 is about 22832.1050277893. The cubic root of 521305020 is about 804.8172984035.

Adding to 521305020 its reverse (20503125), we get a palindrome (541808145).

The spelling of 521305020 in words is "five hundred twenty-one million, three hundred five thousand, twenty".