20511017 has 2 divisors, whose sum is σ = 20511018. Its totient is φ = 20511016.

The previous prime is 20511011. The next prime is 20511031. The reversal of 20511017 is 71011502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19044496 + 1466521 = 4364^2 + 1211^2 .

It is a cyclic number.

It is not a de Polignac number, because 20511017 - 2¹² = 20506921 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20510986 and 20511004.

It is not a weakly prime, because it can be changed into another prime (20511011) 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, 10255508 + 10255509.

It is an arithmetic number, because the mean of its divisors is an integer number (10255509).

Almost surely, 2^20511017 is an apocalyptic number.

It is an amenable number.

20511017 is a deficient number, since it is larger than the sum of its proper divisors (1).

20511017 is an equidigital number, since it uses as much as digits as its factorization.

20511017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 70, while the sum is 17.

The square root of 20511017 is about 4528.9090297775. The cubic root of 20511017 is about 273.7342024341.

Adding to 20511017 its reverse (71011502), we get a palindrome (91522519).

The spelling of 20511017 in words is "twenty million, five hundred eleven thousand, seventeen".