20403289 has 3 divisors (see below), whose sum is σ = 20407807. Its totient is φ = 20398772.

The previous prime is 20403241. The next prime is 20403293. The reversal of 20403289 is 98230402.

The square root of 20403289 is 4517.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 81225 + 20322064 = 285^2 + 4508^2 .

It is not a de Polignac number, because 20403289 - 2¹⁵ = 20370521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20403389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2259 + ... + 6775.

Almost surely, 2^20403289 is an apocalyptic number.

20403289 is the 4517-th square number.

20403289 is the 2259-th centered octagonal number.

It is an amenable number.

20403289 is a deficient number, since it is larger than the sum of its proper divisors (4518).

20403289 is an frugal number, since it uses more digits than its factorization.

20403289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9034 (or 4517 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The cubic root of 20403289 is about 273.2541252080.

It can be divided in two parts, 2040 and 3289, that added together give a square (5329 = 73²).

The spelling of 20403289 in words is "twenty million, four hundred three thousand, two hundred eighty-nine".