521404416 has 228 divisors, whose sum is σ = 1717564212. Its totient is φ = 150994944.

The previous prime is 521404397. The next prime is 521404447. The reversal of 521404416 is 614404125.

521404416 is a `hidden beast` number, since 5 + 214 + 0 + 441 + 6 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 235929600 + 285474816 = 15360^2 + 16896^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 521404416.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30670840 + ... + 30670856.

Almost surely, 2^521404416 is an apocalyptic number.

521404416 is a droll number since its even prime factors and its odd prime factors have the same sum.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 521404416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (858782106).

521404416 is an abundant number, since it is smaller than the sum of its proper divisors (1196159796).

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

521404416 is an equidigital number, since it uses as much as digits as its factorization.

521404416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72 (or 35 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 521404416 is about 22834.2815958812. The cubic root of 521404416 is about 804.8684460256.

The spelling of 521404416 in words is "five hundred twenty-one million, four hundred four thousand, four hundred sixteen".