16556641 has 2 divisors, whose sum is σ = 16556642. Its totient is φ = 16556640.

The previous prime is 16556629. The next prime is 16556663. The reversal of 16556641 is 14665561.

It is a happy number.

16556641 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13653025 + 2903616 = 3695^2 + 1704^2 .

It is a cyclic number.

It is not a de Polignac number, because 16556641 - 2⁷ = 16556513 is a prime.

It is a super-2 number, since 2×16556641² = 548244722405762, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 16556597 and 16556606.

It is not a weakly prime, because it can be changed into another prime (16556671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8278320 + 8278321.

It is an arithmetic number, because the mean of its divisors is an integer number (8278321).

Almost surely, 2^16556641 is an apocalyptic number.

It is an amenable number.

16556641 is a deficient number, since it is larger than the sum of its proper divisors (1).

16556641 is an equidigital number, since it uses as much as digits as its factorization.

16556641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21600, while the sum is 34.

The square root of 16556641 is about 4068.9852543355. The cubic root of 16556641 is about 254.8731446441.

The spelling of 16556641 in words is "sixteen million, five hundred fifty-six thousand, six hundred forty-one".