18012019999991 has 2 divisors, whose sum is σ = 18012019999992. Its totient is φ = 18012019999990.

The previous prime is 18012019999969. The next prime is 18012020000033. The reversal of 18012019999991 is 19999991021081.

It is a weak prime.

It is an emirp because it is prime and its reverse (19999991021081) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18012019999991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18012019399991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9006009999995 + 9006009999996.

It is an arithmetic number, because the mean of its divisors is an integer number (9006009999996).

Almost surely, 2^{18012019999991} is an apocalyptic number.

18012019999991 is a deficient number, since it is larger than the sum of its proper divisors (1).

18012019999991 is an equidigital number, since it uses as much as digits as its factorization.

18012019999991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8503056, while the sum is 68.

The spelling of 18012019999991 in words is "eighteen trillion, twelve billion, nineteen million, nine hundred ninety-nine thousand, nine hundred ninety-one".