521916 has 48 divisors (see below), whose sum is σ = 1333248. Its totient is φ = 158400.

The previous prime is 521903. The next prime is 521923. The reversal of 521916 is 619125.

It is a super-2 number, since 2×521916² = 544792622112, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8526 + ... + 8586.

It is an arithmetic number, because the mean of its divisors is an integer number (27776).

2⁵²¹⁹¹⁶ 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 521916, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (666624).

521916 is an abundant number, since it is smaller than the sum of its proper divisors (811332).

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

521916 is a wasteful number, since it uses less digits than its factorization.

521916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 120 counting only the distinct ones).

The product of its digits is 540, while the sum is 24.

The square root of 521916 is about 722.4375405528. The cubic root of 521916 is about 80.5131596351.

The spelling of 521916 in words is "five hundred twenty-one thousand, nine hundred sixteen".