20545549 has 4 divisors (see below), whose sum is σ = 20555836. Its totient is φ = 20535264.

The previous prime is 20545531. The next prime is 20545573. The reversal of 20545549 is 94554502.

It is a happy 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 2 ways, for example, as 20412324 + 133225 = 4518^2 + 365^2 .

It is a cyclic number.

It is not a de Polignac number, because 20545549 - 2⁹ = 20545037 is a prime.

It is a super-2 number, since 2×20545549² = 844239167422802, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20045549) 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, 1074 + ... + 6499.

It is an arithmetic number, because the mean of its divisors is an integer number (5138959).

Almost surely, 2^20545549 is an apocalyptic number.

It is an amenable number.

20545549 is a deficient number, since it is larger than the sum of its proper divisors (10287).

20545549 is an equidigital number, since it uses as much as digits as its factorization.

20545549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10286.

The product of its (nonzero) digits is 36000, while the sum is 34.

The square root of 20545549 is about 4532.7198236820. The cubic root of 20545549 is about 273.8877343904.

It can be divided in two parts, 205 and 45549, that added together give a palindrome (45754).

The spelling of 20545549 in words is "twenty million, five hundred forty-five thousand, five hundred forty-nine".