16521040 has 40 divisors (see below), whose sum is σ = 38825640. Its totient is φ = 6537216.

The previous prime is 16521031. The next prime is 16521053. The reversal of 16521040 is 4012561.

16521040 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 456976 + 16064064 = 676^2 + 4008^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 16520999 and 16521017.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6696 + ... + 8824.

It is an arithmetic number, because the mean of its divisors is an integer number (970641).

Almost surely, 2^16521040 is an apocalyptic number.

16521040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16521040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19412820).

16521040 is an abundant number, since it is smaller than the sum of its proper divisors (22304600).

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

16521040 is a wasteful number, since it uses less digits than its factorization.

16521040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2239 (or 2233 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 16521040 is about 4064.6082222030. The cubic root of 16521040 is about 254.6903328000.

The spelling of 16521040 in words is "sixteen million, five hundred twenty-one thousand, forty".