16681556 has 12 divisors (see below), whose sum is σ = 30910068. Its totient is φ = 7850112.

The previous prime is 16681523. The next prime is 16681579. The reversal of 16681556 is 65518661.

It can be written as a sum of positive squares in 2 ways, for example, as 12816400 + 3865156 = 3580^2 + 1966^2 .

It is a super-2 number, since 2×16681556² = 556548621162272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122591 + ... + 122726.

It is an arithmetic number, because the mean of its divisors is an integer number (2575839).

Almost surely, 2^16681556 is an apocalyptic number.

It is an amenable number.

16681556 is a deficient number, since it is larger than the sum of its proper divisors (14228512).

16681556 is a wasteful number, since it uses less digits than its factorization.

16681556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245338 (or 245336 counting only the distinct ones).

The product of its digits is 43200, while the sum is 38.

The square root of 16681556 is about 4084.3060610096. The cubic root of 16681556 is about 255.5125204016.

The spelling of 16681556 in words is "sixteen million, six hundred eighty-one thousand, five hundred fifty-six".