20889545 has 4 divisors (see below), whose sum is σ = 25067460. Its totient is φ = 16711632.

The previous prime is 20889521. The next prime is 20889551. The reversal of 20889545 is 54598802.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14227984 + 6661561 = 3772^2 + 2581^2 .

It is a cyclic number.

It is not a de Polignac number, because 20889545 - 2¹⁰ = 20888521 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2088950 + ... + 2088959.

It is an arithmetic number, because the mean of its divisors is an integer number (6266865).

Almost surely, 2^20889545 is an apocalyptic number.

It is an amenable number.

20889545 is a deficient number, since it is larger than the sum of its proper divisors (4177915).

20889545 is an equidigital number, since it uses as much as digits as its factorization.

20889545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4177914.

The product of its (nonzero) digits is 115200, while the sum is 41.

The square root of 20889545 is about 4570.5081774350. The cubic root of 20889545 is about 275.4078576097.

The spelling of 20889545 in words is "twenty million, eight hundred eighty-nine thousand, five hundred forty-five".