16654561 has 27 divisors (see below), whose sum is σ = 21704403. Its totient is φ = 12732720.

The previous prime is 16654559. The next prime is 16654567. The reversal of 16654561 is 16545661.

It is a happy number.

The square root of 16654561 is 4081.

It is a perfect power (a square), and thus also a powerful number.

16654561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 12006225 + 4648336 = 3465^2 + 2156^2 .

It is not a de Polignac number, because 16654561 - 2¹ = 16654559 is a prime.

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (16654567) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 314211 + ... + 314263.

Almost surely, 2^16654561 is an apocalyptic number.

16654561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

16654561 is the 4081-st square number.

16654561 is the 2041-st centered octagonal number.

It is an amenable number.

16654561 is a deficient number, since it is larger than the sum of its proper divisors (5049842).

16654561 is an equidigital number, since it uses as much as digits as its factorization.

16654561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142 (or 71 counting only the distinct ones).

The product of its digits is 21600, while the sum is 34.

The cubic root of 16654561 is about 255.3746179081.

Subtracting from 16654561 its reverse (16545661), we obtain a square (108900 = 330²).

It can be divided in two parts, 1665 and 4561, that added together give a palindrome (6226).

The spelling of 16654561 in words is "sixteen million, six hundred fifty-four thousand, five hundred sixty-one".