19090891 has 2 divisors, whose sum is σ = 19090892. Its totient is φ = 19090890.

The previous prime is 19090889. The next prime is 19090909. The reversal of 19090891 is 19809091.

It is a weak prime.

It is an emirp because it is prime and its reverse (19809091) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19090891 - 2¹ = 19090889 is a prime.

Together with 19090889, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 19090891.

It is not a weakly prime, because it can be changed into another prime (19090811) 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, 9545445 + 9545446.

It is an arithmetic number, because the mean of its divisors is an integer number (9545446).

Almost surely, 2^19090891 is an apocalyptic number.

19090891 is a deficient number, since it is larger than the sum of its proper divisors (1).

19090891 is an equidigital number, since it uses as much as digits as its factorization.

19090891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 37.

The square root of 19090891 is about 4369.3124173032. The cubic root of 19090891 is about 267.2649858892.

The spelling of 19090891 in words is "nineteen million, ninety thousand, eight hundred ninety-one".