16561155 has 48 divisors (see below), whose sum is σ = 29514240. Its totient is φ = 7922304.

The previous prime is 16561147. The next prime is 16561157. The reversal of 16561155 is 55116561.

16561155 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 16561155 - 2³ = 16561147 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16561157) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 119076 + ... + 119214.

It is an arithmetic number, because the mean of its divisors is an integer number (614880).

Almost surely, 2^16561155 is an apocalyptic number.

16561155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

16561155 is a deficient number, since it is larger than the sum of its proper divisors (12953085).

16561155 is a wasteful number, since it uses less digits than its factorization.

16561155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220 (or 207 counting only the distinct ones).

The product of its digits is 4500, while the sum is 30.

The square root of 16561155 is about 4069.5399002836. The cubic root of 16561155 is about 254.8963053974.

The spelling of 16561155 in words is "sixteen million, five hundred sixty-one thousand, one hundred fifty-five".