16555861 has 8 divisors (see below), whose sum is σ = 18958400. Its totient is φ = 14162688.

The previous prime is 16555849. The next prime is 16555867. The reversal of 16555861 is 16855561.

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

It is a cyclic number.

It is not a de Polignac number, because 16555861 - 2¹⁷ = 16424789 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 16555861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16555867) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1990 + ... + 6088.

It is an arithmetic number, because the mean of its divisors is an integer number (2369800).

Almost surely, 2^16555861 is an apocalyptic number.

It is an amenable number.

16555861 is a deficient number, since it is larger than the sum of its proper divisors (2402539).

16555861 is an equidigital number, since it uses as much as digits as its factorization.

16555861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4683.

The product of its digits is 36000, while the sum is 37.

The square root of 16555861 is about 4068.8894062139. The cubic root of 16555861 is about 254.8691421379.

The spelling of 16555861 in words is "sixteen million, five hundred fifty-five thousand, eight hundred sixty-one".