20544431 has 4 divisors (see below), whose sum is σ = 20554392. Its totient is φ = 20534472.

The previous prime is 20544427. The next prime is 20544439. The reversal of 20544431 is 13444502.

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 is a cyclic number.

It is not a de Polignac number, because 20544431 - 2² = 20544427 is a prime.

It is a super-2 number, since 2×20544431² = 844147290227522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20544397 and 20544406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20544439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 605 + ... + 6438.

It is an arithmetic number, because the mean of its divisors is an integer number (5138598).

Almost surely, 2^20544431 is an apocalyptic number.

20544431 is a deficient number, since it is larger than the sum of its proper divisors (9961).

20544431 is an equidigital number, since it uses as much as digits as its factorization.

20544431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9960.

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 20544431 is about 4532.5964964907. The cubic root of 20544431 is about 273.8827663713.

Adding to 20544431 its reverse (13444502), we get a palindrome (33988933).

The spelling of 20544431 in words is "twenty million, five hundred forty-four thousand, four hundred thirty-one".