20748559 has 4 divisors (see below), whose sum is σ = 22344616. Its totient is φ = 19152504.

The previous prime is 20748557. The next prime is 20748577. The reversal of 20748559 is 95584702.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 95584702 = 2 ⋅47792351.

It is a cyclic number.

It is not a de Polignac number, because 20748559 - 2¹ = 20748557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20748557) 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 3 ways as a sum of consecutive naturals, for example, 798009 + ... + 798034.

It is an arithmetic number, because the mean of its divisors is an integer number (5586154).

Almost surely, 2^20748559 is an apocalyptic number.

20748559 is a deficient number, since it is larger than the sum of its proper divisors (1596057).

20748559 is a wasteful number, since it uses less digits than its factorization.

20748559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1596056.

The product of its (nonzero) digits is 100800, while the sum is 40.

The square root of 20748559 is about 4555.0586165273. The cubic root of 20748559 is about 274.7868717804.

The spelling of 20748559 in words is "twenty million, seven hundred forty-eight thousand, five hundred fifty-nine".