16566516 has 18 divisors (see below), whose sum is σ = 41876562. Its totient is φ = 5522160.

The previous prime is 16566503. The next prime is 16566527. The reversal of 16566516 is 61566561.

It can be written as a sum of positive squares in only one way, i.e., 15920100 + 646416 = 3990^2 + 804^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 460181 = 16566516 / (1 + 6 + 5 + 6 + 6 + 5 + 1 + 6).

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, 230055 + ... + 230126.

Almost surely, 2^16566516 is an apocalyptic number.

It is an amenable number.

16566516 is an abundant number, since it is smaller than the sum of its proper divisors (25310046).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16566516 is a wasteful number, since it uses less digits than its factorization.

16566516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 460191 (or 460186 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 16566516 is about 4070.1985209569. The cubic root of 16566516 is about 254.9238065322.

The spelling of 16566516 in words is "sixteen million, five hundred sixty-six thousand, five hundred sixteen".