20686529 has 2 divisors, whose sum is σ = 20686530. Its totient is φ = 20686528.

The previous prime is 20686513. The next prime is 20686543. The reversal of 20686529 is 92568602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19562929 + 1123600 = 4423^2 + 1060^2 .

It is a cyclic number.

It is not a de Polignac number, because 20686529 - 2⁴ = 20686513 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20686492 and 20686501.

It is not a weakly prime, because it can be changed into another prime (20686559) 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, 10343264 + 10343265.

It is an arithmetic number, because the mean of its divisors is an integer number (10343265).

Almost surely, 2^20686529 is an apocalyptic number.

It is an amenable number.

20686529 is a deficient number, since it is larger than the sum of its proper divisors (1).

20686529 is an equidigital number, since it uses as much as digits as its factorization.

20686529 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51840, while the sum is 38.

The square root of 20686529 is about 4548.2446064388. The cubic root of 20686529 is about 274.5127636862.

The spelling of 20686529 in words is "twenty million, six hundred eighty-six thousand, five hundred twenty-nine".