100666543 has 4 divisors (see below), whose sum is σ = 100688328. Its totient is φ = 100644760.

The previous prime is 100666523. The next prime is 100666547. The reversal of 100666543 is 345666001.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 345666001 = 79 ⋅4375519.

It is a cyclic number.

It is not a de Polignac number, because 100666543 - 2¹³ = 100658351 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100666547) 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, 913 + ... + 14218.

It is an arithmetic number, because the mean of its divisors is an integer number (25172082).

Almost surely, 2^100666543 is an apocalyptic number.

100666543 is a deficient number, since it is larger than the sum of its proper divisors (21785).

100666543 is an equidigital number, since it uses as much as digits as its factorization.

100666543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21784.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 100666543 is about 10033.2717993683. The cubic root of 100666543 is about 465.1878733648.

The spelling of 100666543 in words is "one hundred million, six hundred sixty-six thousand, five hundred forty-three".