16550561 has 8 divisors (see below), whose sum is σ = 17214120. Its totient is φ = 15893248.

The previous prime is 16550557. The next prime is 16550587. The reversal of 16550561 is 16505561.

16550561 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 4 ways, for example, as 3876961 + 12673600 = 1969^2 + 3560^2 .

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 16550561 - 2² = 16550557 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16550461) 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, 4265 + ... + 7161.

It is an arithmetic number, because the mean of its divisors is an integer number (2151765).

Almost surely, 2^16550561 is an apocalyptic number.

It is an amenable number.

16550561 is a deficient number, since it is larger than the sum of its proper divisors (663559).

16550561 is a wasteful number, since it uses less digits than its factorization.

16550561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3123.

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

The square root of 16550561 is about 4068.2380707132. The cubic root of 16550561 is about 254.8419422916.

The spelling of 16550561 in words is "sixteen million, five hundred fifty thousand, five hundred sixty-one".