1915891057 has 2 divisors, whose sum is σ = 1915891058. Its totient is φ = 1915891056.

The previous prime is 1915890997. The next prime is 1915891067. The reversal of 1915891057 is 7501985191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1862440336 + 53450721 = 43156^2 + 7311^2 .

It is an emirp because it is prime and its reverse (7501985191) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1915891057 - 2¹¹ = 1915889009 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1915890998 and 1915891016.

It is not a weakly prime, because it can be changed into another prime (1915891067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 957945528 + 957945529.

It is an arithmetic number, because the mean of its divisors is an integer number (957945529).

Almost surely, 2^1915891057 is an apocalyptic number.

It is an amenable number.

1915891057 is a deficient number, since it is larger than the sum of its proper divisors (1).

1915891057 is an equidigital number, since it uses as much as digits as its factorization.

1915891057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 113400, while the sum is 46.

The square root of 1915891057 is about 43770.8928056077. The cubic root of 1915891057 is about 1242.0057412804.

It can be divided in two parts, 19158 and 91057, that added together give a triangular number (110215 = T₄₆₉).

The spelling of 1915891057 in words is "one billion, nine hundred fifteen million, eight hundred ninety-one thousand, fifty-seven".