66123543 has 4 divisors (see below), whose sum is σ = 88164728. Its totient is φ = 44082360.

The previous prime is 66123517. The next prime is 66123569. The reversal of 66123543 is 34532166.

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

It is an interprime number because it is at equal distance from previous prime (66123517) and next prime (66123569).

It is not a de Polignac number, because 66123543 - 2⁶ = 66123479 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66123543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66123583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11020588 + ... + 11020593.

It is an arithmetic number, because the mean of its divisors is an integer number (22041182).

Almost surely, 2^66123543 is an apocalyptic number.

66123543 is a deficient number, since it is larger than the sum of its proper divisors (22041185).

66123543 is a wasteful number, since it uses less digits than its factorization.

66123543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22041184.

The product of its digits is 12960, while the sum is 30.

The square root of 66123543 is about 8131.6383957970. The cubic root of 66123543 is about 404.3759999004.

It can be divided in two parts, 66123 and 543, that added together give a palindrome (66666).

The spelling of 66123543 in words is "sixty-six million, one hundred twenty-three thousand, five hundred forty-three".