16516521 has 32 divisors (see below), whose sum is σ = 28876800. Its totient is φ = 9130320.

The previous prime is 16516471. The next prime is 16516579. The reversal of 16516521 is 12561561.

It is a happy number.

16516521 is a `hidden beast` number, since 1 + 6 + 5 + 1 + 652 + 1 = 666.

16516521 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 16516521 - 2⁹ = 16516009 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (16516021) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4450 + ... + 7268.

It is an arithmetic number, because the mean of its divisors is an integer number (902400).

Almost surely, 2^16516521 is an apocalyptic number.

It is an amenable number.

16516521 is a deficient number, since it is larger than the sum of its proper divisors (12360279).

16516521 is a wasteful number, since it uses less digits than its factorization.

16516521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2866 (or 2860 counting only the distinct ones).

The product of its digits is 1800, while the sum is 27.

The square root of 16516521 is about 4064.0522880495. The cubic root of 16516521 is about 254.6671088672.

It can be divided in two parts, 1651652 and 1, that added together give a triangular number (1651653 = T₁₈₁₇).

The spelling of 16516521 in words is "sixteen million, five hundred sixteen thousand, five hundred twenty-one".