20689241 has 2 divisors, whose sum is σ = 20689242. Its totient is φ = 20689240.

The previous prime is 20689237. The next prime is 20689247. The reversal of 20689241 is 14298602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20286016 + 403225 = 4504^2 + 635^2 .

It is a cyclic number.

It is not a de Polignac number, because 20689241 - 2² = 20689237 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20689198 and 20689207.

It is not a weakly prime, because it can be changed into another prime (20689247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10344620 + 10344621.

It is an arithmetic number, because the mean of its divisors is an integer number (10344621).

Almost surely, 2^20689241 is an apocalyptic number.

It is an amenable number.

20689241 is a deficient number, since it is larger than the sum of its proper divisors (1).

20689241 is an equidigital number, since it uses as much as digits as its factorization.

20689241 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 20689241 is about 4548.5427336676. The cubic root of 20689241 is about 274.5247593523.

The spelling of 20689241 in words is "twenty million, six hundred eighty-nine thousand, two hundred forty-one".