20017649 has 2 divisors, whose sum is σ = 20017650. Its totient is φ = 20017648.

The previous prime is 20017639. The next prime is 20017651. The reversal of 20017649 is 94671002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11607649 + 8410000 = 3407^2 + 2900^2 .

It is a cyclic number.

It is not a de Polignac number, because 20017649 - 2⁴ = 20017633 is a prime.

Together with 20017651, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_1271666 and since 20017649 and 1271666 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (20017639) by changing a digit.

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 as a sum of consecutive naturals, namely, 10008824 + 10008825.

It is an arithmetic number, because the mean of its divisors is an integer number (10008825).

Almost surely, 2^20017649 is an apocalyptic number.

It is an amenable number.

20017649 is a deficient number, since it is larger than the sum of its proper divisors (1).

20017649 is an equidigital number, since it uses as much as digits as its factorization.

20017649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 20017649 is about 4474.1087380617. The cubic root of 20017649 is about 271.5215827789.

The spelling of 20017649 in words is "twenty million, seventeen thousand, six hundred forty-nine".