16600561 has 4 divisors (see below), whose sum is σ = 16696692. Its totient is φ = 16504432.

The previous prime is 16600559. The next prime is 16600567. The reversal of 16600561 is 16500661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16500661 = 3191 ⋅5171.

It can be written as a sum of positive squares in 2 ways, for example, as 12110400 + 4490161 = 3480^2 + 2119^2 .

It is a cyclic number.

It is not a de Polignac number, because 16600561 - 2¹ = 16600559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16600567) 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, 47806 + ... + 48151.

It is an arithmetic number, because the mean of its divisors is an integer number (4174173).

Almost surely, 2^16600561 is an apocalyptic number.

It is an amenable number.

16600561 is a deficient number, since it is larger than the sum of its proper divisors (96131).

16600561 is an equidigital number, since it uses as much as digits as its factorization.

16600561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96130.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 16600561 is about 4074.3786029283. The cubic root of 16600561 is about 255.0983140066.

It can be divided in two parts, 16600 and 561, that added together give a square (17161 = 131²).

The spelling of 16600561 in words is "sixteen million, six hundred thousand, five hundred sixty-one".