521856 has 64 divisors (see below), whose sum is σ = 1550400. Its totient is φ = 172800.

The previous prime is 521831. The next prime is 521861. The reversal of 521856 is 658125.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an alternating number because its digits alternate between odd and even.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 521856.

It is an unprimeable number.

521856 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3381 + ... + 3531.

It is an arithmetic number, because the mean of its divisors is an integer number (24225).

2⁵²¹⁸⁵⁶ 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 521856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (775200).

521856 is an abundant number, since it is smaller than the sum of its proper divisors (1028544).

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

521856 is a wasteful number, since it uses less digits than its factorization.

521856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174 (or 156 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

The square root of 521856 is about 722.3960132780. The cubic root of 521856 is about 80.5100742250.

The spelling of 521856 in words is "five hundred twenty-one thousand, eight hundred fifty-six".