16681001 has 2 divisors, whose sum is σ = 16681002. Its totient is φ = 16681000.

The previous prime is 16680977. The next prime is 16681013. The reversal of 16681001 is 10018661.

It is a happy number.

16681001 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16410601 + 270400 = 4051^2 + 520^2 .

It is a cyclic number.

It is not a de Polignac number, because 16681001 - 2¹⁰ = 16679977 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (16681051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8340500 + 8340501.

It is an arithmetic number, because the mean of its divisors is an integer number (8340501).

Almost surely, 2^16681001 is an apocalyptic number.

It is an amenable number.

16681001 is a deficient number, since it is larger than the sum of its proper divisors (1).

16681001 is an equidigital number, since it uses as much as digits as its factorization.

16681001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 16681001 is about 4084.2381174461. The cubic root of 16681001 is about 255.5096867127.

Adding to 16681001 its reverse (10018661), we get a palindrome (26699662).

The spelling of 16681001 in words is "sixteen million, six hundred eighty-one thousand, one".