20688533 has 2 divisors, whose sum is σ = 20688534. Its totient is φ = 20688532.

The previous prime is 20688529. The next prime is 20688539. The reversal of 20688533 is 33588602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18722929 + 1965604 = 4327^2 + 1402^2 .

It is a cyclic number.

It is not a de Polignac number, because 20688533 - 2² = 20688529 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20688493 and 20688502.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20688539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10344266 + 10344267.

It is an arithmetic number, because the mean of its divisors is an integer number (10344267).

Almost surely, 2^20688533 is an apocalyptic number.

It is an amenable number.

20688533 is a deficient number, since it is larger than the sum of its proper divisors (1).

20688533 is an equidigital number, since it uses as much as digits as its factorization.

20688533 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34560, while the sum is 35.

The square root of 20688533 is about 4548.4649058776. The cubic root of 20688533 is about 274.5216278415.

It can be divided in two parts, 2068 and 8533, that added together give a palindrome (10601).

The spelling of 20688533 in words is "twenty million, six hundred eighty-eight thousand, five hundred thirty-three".