66442543 has 4 divisors (see below), whose sum is σ = 66461848. Its totient is φ = 66423240.

The previous prime is 66442507. The next prime is 66442559. The reversal of 66442543 is 34524466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34524466 = 2 ⋅17262233.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66442543 is a prime.

It is a super-2 number, since 2×66442543² = 8829223040613698, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66442499 and 66442508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66442573) 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, 2928 + ... + 11893.

It is an arithmetic number, because the mean of its divisors is an integer number (16615462).

Almost surely, 2^66442543 is an apocalyptic number.

66442543 is a deficient number, since it is larger than the sum of its proper divisors (19305).

66442543 is a wasteful number, since it uses less digits than its factorization.

66442543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19304.

The product of its digits is 69120, while the sum is 34.

The square root of 66442543 is about 8151.2295391554. The cubic root of 66442543 is about 405.0252344181.

The spelling of 66442543 in words is "sixty-six million, four hundred forty-two thousand, five hundred forty-three".