18971943 has 4 divisors (see below), whose sum is σ = 25295928. Its totient is φ = 12647960.

The previous prime is 18971923. The next prime is 18971947. The reversal of 18971943 is 34917981.

It is a happy number.

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 18971943 - 2¹³ = 18963751 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18971895 and 18971904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18971947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3161988 + ... + 3161993.

It is an arithmetic number, because the mean of its divisors is an integer number (6323982).

Almost surely, 2^18971943 is an apocalyptic number.

18971943 is a deficient number, since it is larger than the sum of its proper divisors (6323985).

18971943 is an equidigital number, since it uses as much as digits as its factorization.

18971943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6323984.

The product of its digits is 54432, while the sum is 42.

The square root of 18971943 is about 4355.6793959152. The cubic root of 18971943 is about 266.7087539474.

The spelling of 18971943 in words is "eighteen million, nine hundred seventy-one thousand, nine hundred forty-three".