20408543 has 2 divisors, whose sum is σ = 20408544. Its totient is φ = 20408542.

The previous prime is 20408533. The next prime is 20408561. The reversal of 20408543 is 34580402.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20408543 - 2¹⁴ = 20392159 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20408533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10204271 + 10204272.

It is an arithmetic number, because the mean of its divisors is an integer number (10204272).

Almost surely, 2^20408543 is an apocalyptic number.

20408543 is a deficient number, since it is larger than the sum of its proper divisors (1).

20408543 is an equidigital number, since it uses as much as digits as its factorization.

20408543 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3840, while the sum is 26.

The square root of 20408543 is about 4517.5815432596. The cubic root of 20408543 is about 273.2775781908.

Adding to 20408543 its reverse (34580402), we get a palindrome (54988945).

The spelling of 20408543 in words is "twenty million, four hundred eight thousand, five hundred forty-three".