20389549 has 2 divisors, whose sum is σ = 20389550. Its totient is φ = 20389548.

The previous prime is 20389547. The next prime is 20389561. The reversal of 20389549 is 94598302.

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., 20187049 + 202500 = 4493^2 + 450^2 .

It is a cyclic number.

It is not a de Polignac number, because 20389549 - 2¹ = 20389547 is a prime.

Together with 20389547, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20389541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10194774 + 10194775.

It is an arithmetic number, because the mean of its divisors is an integer number (10194775).

Almost surely, 2^20389549 is an apocalyptic number.

It is an amenable number.

20389549 is a deficient number, since it is larger than the sum of its proper divisors (1).

20389549 is an equidigital number, since it uses as much as digits as its factorization.

20389549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 77760, while the sum is 40.

The square root of 20389549 is about 4515.4788228935. The cubic root of 20389549 is about 273.1927730932.

The spelling of 20389549 in words is "twenty million, three hundred eighty-nine thousand, five hundred forty-nine".