5518325991991 has 2 divisors, whose sum is σ = 5518325991992. Its totient is φ = 5518325991990.

The previous prime is 5518325991961. The next prime is 5518325992043. The reversal of 5518325991991 is 1991995238155.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 5518325991991 - 2³¹ = 5516178508343 is a prime.

It is a super-2 number, since 2×5518325991991² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5518325991911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2759162995995 + 2759162995996.

It is an arithmetic number, because the mean of its divisors is an integer number (2759162995996).

Almost surely, 2^{5518325991991} is an apocalyptic number.

5518325991991 is a deficient number, since it is larger than the sum of its proper divisors (1).

5518325991991 is an equidigital number, since it uses as much as digits as its factorization.

5518325991991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 39366000, while the sum is 67.

The spelling of 5518325991991 in words is "five trillion, five hundred eighteen billion, three hundred twenty-five million, nine hundred ninety-one thousand, nine hundred ninety-one".