18891043 has 2 divisors, whose sum is σ = 18891044. Its totient is φ = 18891042.

The previous prime is 18891031. The next prime is 18891071. The reversal of 18891043 is 34019881.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18891043 is a prime.

It is not a weakly prime, because it can be changed into another prime (18891023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9445521 + 9445522.

It is an arithmetic number, because the mean of its divisors is an integer number (9445522).

Almost surely, 2^18891043 is an apocalyptic number.

18891043 is a deficient number, since it is larger than the sum of its proper divisors (1).

18891043 is an equidigital number, since it uses as much as digits as its factorization.

18891043 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 18891043 is about 4346.3827489074. The cubic root of 18891043 is about 266.3291147407.

The spelling of 18891043 in words is "eighteen million, eight hundred ninety-one thousand, forty-three".