20748289 has 4 divisors (see below), whose sum is σ = 20761300. Its totient is φ = 20735280.

The previous prime is 20748271. The next prime is 20748319. The reversal of 20748289 is 98284702.

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 1912689 + 18835600 = 1383^2 + 4340^2 .

It is a cyclic number.

It is not a de Polignac number, because 20748289 - 2⁹ = 20747777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20748229) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3714 + ... + 7435.

It is an arithmetic number, because the mean of its divisors is an integer number (5190325).

Almost surely, 2^20748289 is an apocalyptic number.

It is an amenable number.

20748289 is a deficient number, since it is larger than the sum of its proper divisors (13011).

20748289 is a wasteful number, since it uses less digits than its factorization.

20748289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13010.

The product of its (nonzero) digits is 64512, while the sum is 40.

The square root of 20748289 is about 4555.0289790516. The cubic root of 20748289 is about 274.7856798458.

The spelling of 20748289 in words is "twenty million, seven hundred forty-eight thousand, two hundred eighty-nine".