1891159447 has 2 divisors, whose sum is σ = 1891159448. Its totient is φ = 1891159446.

The previous prime is 1891159367. The next prime is 1891159477. The reversal of 1891159447 is 7449511981.

It is a strong prime.

It is an emirp because it is prime and its reverse (7449511981) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1891159447 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1891159447.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1891159477) 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, 945579723 + 945579724.

It is an arithmetic number, because the mean of its divisors is an integer number (945579724).

Almost surely, 2^1891159447 is an apocalyptic number.

1891159447 is a deficient number, since it is larger than the sum of its proper divisors (1).

1891159447 is an equidigital number, since it uses as much as digits as its factorization.

1891159447 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 49.

The square root of 1891159447 is about 43487.4631014503. The cubic root of 1891159447 is about 1236.6383642855.

The spelling of 1891159447 in words is "one billion, eight hundred ninety-one million, one hundred fifty-nine thousand, four hundred forty-seven".