18443315531 has 2 divisors, whose sum is σ = 18443315532. Its totient is φ = 18443315530.

The previous prime is 18443315389. The next prime is 18443315533. The reversal of 18443315531 is 13551334481.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18443315531 - 2³⁰ = 17369573707 is a prime.

It is a super-2 number, since 2×18443315531² (a number of 21 digits) contains 22 as substring.

Together with 18443315533, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18443315533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9221657765 + 9221657766.

It is an arithmetic number, because the mean of its divisors is an integer number (9221657766).

Almost surely, 2^18443315531 is an apocalyptic number.

18443315531 is a deficient number, since it is larger than the sum of its proper divisors (1).

18443315531 is an equidigital number, since it uses as much as digits as its factorization.

18443315531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 86400, while the sum is 38.

The spelling of 18443315531 in words is "eighteen billion, four hundred forty-three million, three hundred fifteen thousand, five hundred thirty-one".