18311551249 has 2 divisors, whose sum is σ = 18311551250. Its totient is φ = 18311551248.

The previous prime is 18311551183. The next prime is 18311551273. The reversal of 18311551249 is 94215511381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15565057600 + 2746493649 = 124760^2 + 52407^2 .

It is a cyclic number.

It is not a de Polignac number, because 18311551249 - 2⁷ = 18311551121 is a prime.

It is not a weakly prime, because it can be changed into another prime (18311551949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9155775624 + 9155775625.

It is an arithmetic number, because the mean of its divisors is an integer number (9155775625).

Almost surely, 2^18311551249 is an apocalyptic number.

It is an amenable number.

18311551249 is a deficient number, since it is larger than the sum of its proper divisors (1).

18311551249 is an equidigital number, since it uses as much as digits as its factorization.

18311551249 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43200, while the sum is 40.

The spelling of 18311551249 in words is "eighteen billion, three hundred eleven million, five hundred fifty-one thousand, two hundred forty-nine".