18994823 has 2 divisors, whose sum is σ = 18994824. Its totient is φ = 18994822.

The previous prime is 18994817. The next prime is 18994841. The reversal of 18994823 is 32849981.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (32849981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18994823 - 2¹⁴ = 18978439 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 (18994883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9497411 + 9497412.

It is an arithmetic number, because the mean of its divisors is an integer number (9497412).

Almost surely, 2^18994823 is an apocalyptic number.

18994823 is a deficient number, since it is larger than the sum of its proper divisors (1).

18994823 is an equidigital number, since it uses as much as digits as its factorization.

18994823 is an evil number, because the sum of its binary digits is even.

The product of its digits is 124416, while the sum is 44.

The square root of 18994823 is about 4358.3050604564. The cubic root of 18994823 is about 266.8159270297.

The spelling of 18994823 in words is "eighteen million, nine hundred ninety-four thousand, eight hundred twenty-three".