20989349 has 2 divisors, whose sum is σ = 20989350. Its totient is φ = 20989348.

The previous prime is 20989343. The next prime is 20989391. The reversal of 20989349 is 94398902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17724100 + 3265249 = 4210^2 + 1807^2 .

It is a cyclic number.

It is not a de Polignac number, because 20989349 - 2⁴ = 20989333 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20989343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10494674 + 10494675.

It is an arithmetic number, because the mean of its divisors is an integer number (10494675).

Almost surely, 2^20989349 is an apocalyptic number.

It is an amenable number.

20989349 is a deficient number, since it is larger than the sum of its proper divisors (1).

20989349 is an equidigital number, since it uses as much as digits as its factorization.

20989349 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 20989349 is about 4581.4134281900. The cubic root of 20989349 is about 275.8457664146.

The spelling of 20989349 in words is "twenty million, nine hundred eighty-nine thousand, three hundred forty-nine".