18043999823 has 2 divisors, whose sum is σ = 18043999824. Its totient is φ = 18043999822.

The previous prime is 18043999807. The next prime is 18043999843. The reversal of 18043999823 is 32899934081.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18043999823 - 2⁴ = 18043999807 is a prime.

It is a super-2 number, since 2×18043999823² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18043999843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9021999911 + 9021999912.

It is an arithmetic number, because the mean of its divisors is an integer number (9021999912).

Almost surely, 2^18043999823 is an apocalyptic number.

18043999823 is a deficient number, since it is larger than the sum of its proper divisors (1).

18043999823 is an equidigital number, since it uses as much as digits as its factorization.

18043999823 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3359232, while the sum is 56.

The spelling of 18043999823 in words is "eighteen billion, forty-three million, nine hundred ninety-nine thousand, eight hundred twenty-three".