521940 has 24 divisors (see below), whose sum is σ = 1461600. Its totient is φ = 139168.

The previous prime is 521929. The next prime is 521981. The reversal of 521940 is 49125.

It is a congruent number.

It is an unprimeable number.

521940 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4290 + ... + 4409.

It is an arithmetic number, because the mean of its divisors is an integer number (60900).

2⁵²¹⁹⁴⁰ is an apocalyptic number.

It is an amenable number.

521940 is an abundant number, since it is smaller than the sum of its proper divisors (939660).

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

521940 is a wasteful number, since it uses less digits than its factorization.

521940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8711 (or 8709 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 521940 is about 722.4541507944. The cubic root of 521940 is about 80.5143937329.

It can be divided in two parts, 5 and 21940, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 521940 in words is "five hundred twenty-one thousand, nine hundred forty".