18819863 has 2 divisors, whose sum is σ = 18819864. Its totient is φ = 18819862.

The previous prime is 18819859. The next prime is 18819887. The reversal of 18819863 is 36891881.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18819863 - 2² = 18819859 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18819893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9409931 + 9409932.

It is an arithmetic number, because the mean of its divisors is an integer number (9409932).

Almost surely, 2^18819863 is an apocalyptic number.

18819863 is a deficient number, since it is larger than the sum of its proper divisors (1).

18819863 is an equidigital number, since it uses as much as digits as its factorization.

18819863 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 44.

The square root of 18819863 is about 4338.1866027178. The cubic root of 18819863 is about 265.9941911785.

The spelling of 18819863 in words is "eighteen million, eight hundred nineteen thousand, eight hundred sixty-three".