18943871 has 2 divisors, whose sum is σ = 18943872. Its totient is φ = 18943870.

The previous prime is 18943853. The next prime is 18943879. The reversal of 18943871 is 17834981.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18943871 - 2⁶ = 18943807 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18943879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9471935 + 9471936.

It is an arithmetic number, because the mean of its divisors is an integer number (9471936).

Almost surely, 2^18943871 is an apocalyptic number.

18943871 is a deficient number, since it is larger than the sum of its proper divisors (1).

18943871 is an equidigital number, since it uses as much as digits as its factorization.

18943871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48384, while the sum is 41.

The square root of 18943871 is about 4352.4557436004. The cubic root of 18943871 is about 266.5771430393.

The spelling of 18943871 in words is "eighteen million, nine hundred forty-three thousand, eight hundred seventy-one".