1617187891091 has 2 divisors, whose sum is σ = 1617187891092. Its totient is φ = 1617187891090.

The previous prime is 1617187891079. The next prime is 1617187891093. The reversal of 1617187891091 is 1901987817161.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1617187891091 is a prime.

Together with 1617187891093, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1617187891091.

It is not a weakly prime, because it can be changed into another prime (1617187891093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 808593945545 + 808593945546.

It is an arithmetic number, because the mean of its divisors is an integer number (808593945546).

Almost surely, 2^{1617187891091} is an apocalyptic number.

1617187891091 is a deficient number, since it is larger than the sum of its proper divisors (1).

1617187891091 is an equidigital number, since it uses as much as digits as its factorization.

1617187891091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1524096, while the sum is 59.

The spelling of 1617187891091 in words is "one trillion, six hundred seventeen billion, one hundred eighty-seven million, eight hundred ninety-one thousand, ninety-one".