16561055 has 8 divisors (see below), whose sum is σ = 22712352. Its totient is φ = 11356128.

The previous prime is 16561049. The next prime is 16561057. The reversal of 16561055 is 55016561.

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

It is not a de Polignac number, because 16561055 - 2¹⁸ = 16298911 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16561057) 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, 236552 + ... + 236621.

It is an arithmetic number, because the mean of its divisors is an integer number (2839044).

Almost surely, 2^16561055 is an apocalyptic number.

16561055 is a deficient number, since it is larger than the sum of its proper divisors (6151297).

16561055 is an equidigital number, since it uses as much as digits as its factorization.

16561055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 473185.

The product of its (nonzero) digits is 4500, while the sum is 29.

The square root of 16561055 is about 4069.5276138638. The cubic root of 16561055 is about 254.8957923559.

The spelling of 16561055 in words is "sixteen million, five hundred sixty-one thousand, fifty-five".