17955155155991 has 2 divisors, whose sum is σ = 17955155155992. Its totient is φ = 17955155155990.

The previous prime is 17955155155871. The next prime is 17955155155997. The reversal of 17955155155991 is 19955155155971.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 17955155155991 - 2³⁰ = 17954081414167 is a prime.

It is a super-4 number, since 4×17955155155991⁴ (a number of 54 digits) contains 4444 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (17955155155997) 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, 8977577577995 + 8977577577996.

It is an arithmetic number, because the mean of its divisors is an integer number (8977577577996).

Almost surely, 2^{17955155155991} is an apocalyptic number.

17955155155991 is a deficient number, since it is larger than the sum of its proper divisors (1).

17955155155991 is an equidigital number, since it uses as much as digits as its factorization.

17955155155991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 79734375, while the sum is 68.

The spelling of 17955155155991 in words is "seventeen trillion, nine hundred fifty-five billion, one hundred fifty-five million, one hundred fifty-five thousand, nine hundred ninety-one".