20671543 has 2 divisors, whose sum is σ = 20671544. Its totient is φ = 20671542.

The previous prime is 20671531. The next prime is 20671603. The reversal of 20671543 is 34517602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20671543 - 2¹³ = 20663351 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20674543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10335771 + 10335772.

It is an arithmetic number, because the mean of its divisors is an integer number (10335772).

Almost surely, 2^20671543 is an apocalyptic number.

20671543 is a deficient number, since it is larger than the sum of its proper divisors (1).

20671543 is an equidigital number, since it uses as much as digits as its factorization.

20671543 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 20671543 is about 4546.5968591904. The cubic root of 20671543 is about 274.4464589897.

The spelling of 20671543 in words is "twenty million, six hundred seventy-one thousand, five hundred forty-three".