20005549 has 4 divisors (see below), whose sum is σ = 21182364. Its totient is φ = 18828736.

The previous prime is 20005541. The next prime is 20005589. The reversal of 20005549 is 94550002.

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 16144324 + 3861225 = 4018^2 + 1965^2 .

It is a cyclic number.

It is not a de Polignac number, because 20005549 - 2³ = 20005541 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 (20005541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 588382 + ... + 588415.

It is an arithmetic number, because the mean of its divisors is an integer number (5295591).

Almost surely, 2^20005549 is an apocalyptic number.

It is an amenable number.

20005549 is a deficient number, since it is larger than the sum of its proper divisors (1176815).

20005549 is a wasteful number, since it uses less digits than its factorization.

20005549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1176814.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 20005549 is about 4472.7563090336. The cubic root of 20005549 is about 271.4668631771.

The spelling of 20005549 in words is "twenty million, five thousand, five hundred forty-nine".