20609543 has 2 divisors, whose sum is σ = 20609544. Its totient is φ = 20609542.

The previous prime is 20609539. The next prime is 20609569. The reversal of 20609543 is 34590602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20609543 - 2² = 20609539 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20609573) 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 as a sum of consecutive naturals, namely, 10304771 + 10304772.

It is an arithmetic number, because the mean of its divisors is an integer number (10304772).

Almost surely, 2^20609543 is an apocalyptic number.

20609543 is a deficient number, since it is larger than the sum of its proper divisors (1).

20609543 is an equidigital number, since it uses as much as digits as its factorization.

20609543 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 20609543 is about 4539.7734524974. The cubic root of 20609543 is about 274.1718024966.

The spelling of 20609543 in words is "twenty million, six hundred nine thousand, five hundred forty-three".