20989229 has 2 divisors, whose sum is σ = 20989230. Its totient is φ = 20989228.

The previous prime is 20989223. The next prime is 20989279. The reversal of 20989229 is 92298902.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20884900 + 104329 = 4570^2 + 323^2 .

It is a cyclic number.

It is not a de Polignac number, because 20989229 - 2⁸ = 20988973 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 (20989223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10494614 + 10494615.

It is an arithmetic number, because the mean of its divisors is an integer number (10494615).

Almost surely, 2^20989229 is an apocalyptic number.

It is an amenable number.

20989229 is a deficient number, since it is larger than the sum of its proper divisors (1).

20989229 is an equidigital number, since it uses as much as digits as its factorization.

20989229 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 20989229 is about 4581.4003317763. The cubic root of 20989229 is about 275.8452407265.

The spelling of 20989229 in words is "twenty million, nine hundred eighty-nine thousand, two hundred twenty-nine".