16500521 has 4 divisors (see below), whose sum is σ = 16525572. Its totient is φ = 16475472.

The previous prime is 16500481. The next prime is 16500527. The reversal of 16500521 is 12500561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12500561 = 37 ⋅337853.

It can be written as a sum of positive squares in 2 ways, for example, as 12355225 + 4145296 = 3515^2 + 2036^2 .

It is not a de Polignac number, because 16500521 - 2⁶ = 16500457 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16500493 and 16500502.

It is not an unprimeable number, because it can be changed into a prime (16500527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11510 + ... + 12863.

It is an arithmetic number, because the mean of its divisors is an integer number (4131393).

Almost surely, 2^16500521 is an apocalyptic number.

It is an amenable number.

16500521 is a deficient number, since it is larger than the sum of its proper divisors (25051).

16500521 is an equidigital number, since it uses as much as digits as its factorization.

16500521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25050.

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 16500521 is about 4062.0833324785. The cubic root of 16500521 is about 254.5848479964.

The spelling of 16500521 in words is "sixteen million, five hundred thousand, five hundred twenty-one".