521020116 has 18 divisors (see below), whose sum is σ = 1317023162. Its totient is φ = 173673360.

The previous prime is 521020111. The next prime is 521020117. The reversal of 521020116 is 611020125.

It can be written as a sum of positive squares in only one way, i.e., 518472900 + 2547216 = 22770^2 + 1596^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×521020116² = 542923922553306912, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521020111) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7236355 + ... + 7236426.

Almost surely, 2^521020116 is an apocalyptic number.

It is an amenable number.

521020116 is an abundant number, since it is smaller than the sum of its proper divisors (796003046).

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

521020116 is a wasteful number, since it uses less digits than its factorization.

521020116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14472791 (or 14472786 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 521020116 is about 22825.8650657538. The cubic root of 521020116 is about 804.6706552399.

Subtracting 521020116 from its reverse (611020125), we obtain a palindrome (90000009).

The spelling of 521020116 in words is "five hundred twenty-one million, twenty thousand, one hundred sixteen".