16504561 has 8 divisors (see below), whose sum is σ = 16945280. Its totient is φ = 16066512.

The previous prime is 16504549. The next prime is 16504573. The reversal of 16504561 is 16540561.

It is an interprime number because it is at equal distance from previous prime (16504549) and next prime (16504573).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16504561 - 2⁵ = 16504529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16504541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19495 + ... + 20323.

It is an arithmetic number, because the mean of its divisors is an integer number (2118160).

Almost surely, 2^16504561 is an apocalyptic number.

It is an amenable number.

16504561 is a deficient number, since it is larger than the sum of its proper divisors (440719).

16504561 is an equidigital number, since it uses as much as digits as its factorization.

16504561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1335.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 16504561 is about 4062.5805838162. The cubic root of 16504561 is about 254.6056238829.

The spelling of 16504561 in words is "sixteen million, five hundred four thousand, five hundred sixty-one".