521646 has 16 divisors (see below), whose sum is σ = 1050624. Its totient is φ = 172664.

The previous prime is 521641. The next prime is 521657. The reversal of 521646 is 646125.

It is a super-2 number, since 2×521646² = 544229098632, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1171 + ... + 1553.

It is an arithmetic number, because the mean of its divisors is an integer number (65664).

2⁵²¹⁶⁴⁶ is an apocalyptic number.

521646 is an abundant number, since it is smaller than the sum of its proper divisors (528978).

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

521646 is a wasteful number, since it uses less digits than its factorization.

521646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 615.

The product of its digits is 1440, while the sum is 24.

The square root of 521646 is about 722.2506490132. The cubic root of 521646 is about 80.4992734268.

The spelling of 521646 in words is "five hundred twenty-one thousand, six hundred forty-six".