16561550 has 12 divisors (see below), whose sum is σ = 30804576. Its totient is φ = 6624600.

The previous prime is 16561549. The next prime is 16561577. The reversal of 16561550 is 5516561.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 165566 + ... + 165665.

It is an arithmetic number, because the mean of its divisors is an integer number (2567048).

Almost surely, 2^16561550 is an apocalyptic number.

16561550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16561550 is a deficient number, since it is larger than the sum of its proper divisors (14243026).

16561550 is a wasteful number, since it uses less digits than its factorization.

16561550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331243 (or 331238 counting only the distinct ones).

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

The square root of 16561550 is about 4069.5884312790. The cubic root of 16561550 is about 254.8983318913.

The spelling of 16561550 in words is "sixteen million, five hundred sixty-one thousand, five hundred fifty".