16500561 has 32 divisors (see below), whose sum is σ = 27902976. Its totient is φ = 8424000.

The previous prime is 16500541. The next prime is 16500581.

16500561 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (16500541) and next prime (16500581).

It is not a de Polignac number, because 16500561 - 2⁹ = 16500049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16500541) 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, 13506 + ... + 14676.

It is an arithmetic number, because the mean of its divisors is an integer number (871968).

Almost surely, 2^16500561 is an apocalyptic number.

16500561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16500561 is a deficient number, since it is larger than the sum of its proper divisors (11402415).

16500561 is a wasteful number, since it uses less digits than its factorization.

16500561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1253.

The product of its (nonzero) digits is 900, while the sum is 24.

The square root of 16500561 is about 4062.0882560575. The cubic root of 16500561 is about 254.5850537149.

The spelling of 16500561 in words is "sixteen million, five hundred thousand, five hundred sixty-one".