18640043 has 2 divisors, whose sum is σ = 18640044. Its totient is φ = 18640042.

The previous prime is 18640033. The next prime is 18640067. The reversal of 18640043 is 34004681.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18640043 - 2⁶ = 18639979 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18639994 and 18640021.

It is not a weakly prime, because it can be changed into another prime (18640033) 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 as a sum of consecutive naturals, namely, 9320021 + 9320022.

It is an arithmetic number, because the mean of its divisors is an integer number (9320022).

Almost surely, 2^18640043 is an apocalyptic number.

18640043 is a deficient number, since it is larger than the sum of its proper divisors (1).

18640043 is an equidigital number, since it uses as much as digits as its factorization.

18640043 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 18640043 is about 4317.4116088230. The cubic root of 18640043 is about 265.1443049341.

The spelling of 18640043 in words is "eighteen million, six hundred forty thousand, forty-three".