66543019 has 4 divisors (see below), whose sum is σ = 68689600. Its totient is φ = 64396440.

The previous prime is 66543017. The next prime is 66543031. The reversal of 66543019 is 91034566.

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 66543019 - 2¹ = 66543017 is a prime.

It is a super-2 number, since 2×66543019² = 8855946755268722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66543011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1073244 + ... + 1073305.

It is an arithmetic number, because the mean of its divisors is an integer number (17172400).

Almost surely, 2^66543019 is an apocalyptic number.

66543019 is a deficient number, since it is larger than the sum of its proper divisors (2146581).

66543019 is a wasteful number, since it uses less digits than its factorization.

66543019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2146580.

The product of its (nonzero) digits is 19440, while the sum is 34.

The square root of 66543019 is about 8157.3904528348. The cubic root of 66543019 is about 405.2292945346.

The spelling of 66543019 in words is "sixty-six million, five hundred forty-three thousand, nineteen".