20016649 has 2 divisors, whose sum is σ = 20016650. Its totient is φ = 20016648.

The previous prime is 20016643. The next prime is 20016677. The reversal of 20016649 is 94661002.

It is an a-pointer prime, because the next prime (20016677) can be obtained adding 20016649 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19536400 + 480249 = 4420^2 + 693^2 .

It is a cyclic number.

It is not a de Polignac number, because 20016649 - 2⁹ = 20016137 is a prime.

It is not a weakly prime, because it can be changed into another prime (20016643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10008324 + 10008325.

It is an arithmetic number, because the mean of its divisors is an integer number (10008325).

Almost surely, 2^20016649 is an apocalyptic number.

It is an amenable number.

20016649 is a deficient number, since it is larger than the sum of its proper divisors (1).

20016649 is an equidigital number, since it uses as much as digits as its factorization.

20016649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 20016649 is about 4473.9969825649. The cubic root of 20016649 is about 271.5170613338.

The spelling of 20016649 in words is "twenty million, sixteen thousand, six hundred forty-nine".