16651001 has 2 divisors, whose sum is σ = 16651002. Its totient is φ = 16651000.

The previous prime is 16650989. The next prime is 16651003. The reversal of 16651001 is 10015661.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9765625 + 6885376 = 3125^2 + 2624^2 .

It is an emirp because it is prime and its reverse (10015661) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16651001 is a prime.

Together with 16651003, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (16651003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8325500 + 8325501.

It is an arithmetic number, because the mean of its divisors is an integer number (8325501).

Almost surely, 2^16651001 is an apocalyptic number.

It is an amenable number.

16651001 is a deficient number, since it is larger than the sum of its proper divisors (1).

16651001 is an equidigital number, since it uses as much as digits as its factorization.

16651001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 16651001 is about 4080.5638090832. The cubic root of 16651001 is about 255.3564207222.

Adding to 16651001 its reverse (10015661), we get a palindrome (26666662).

The spelling of 16651001 in words is "sixteen million, six hundred fifty-one thousand, one".