66355543 has 4 divisors (see below), whose sum is σ = 69847960. Its totient is φ = 62863128.

The previous prime is 66355537. The next prime is 66355571. The reversal of 66355543 is 34555366.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66355543 - 2²¹ = 64258391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66355043) 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, 1746180 + ... + 1746217.

It is an arithmetic number, because the mean of its divisors is an integer number (17461990).

Almost surely, 2^66355543 is an apocalyptic number.

66355543 is a deficient number, since it is larger than the sum of its proper divisors (3492417).

66355543 is a wasteful number, since it uses less digits than its factorization.

66355543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3492416.

The product of its digits is 162000, while the sum is 37.

The square root of 66355543 is about 8145.8911728552. The cubic root of 66355543 is about 404.8483769165.

The spelling of 66355543 in words is "sixty-six million, three hundred fifty-five thousand, five hundred forty-three".