1919840257 has 2 divisors, whose sum is σ = 1919840258. Its totient is φ = 1919840256.

The previous prime is 1919840233. The next prime is 1919840309. The reversal of 1919840257 is 7520489191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1197090801 + 722749456 = 34599^2 + 26884^2 .

It is an emirp because it is prime and its reverse (7520489191) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1919840257 is a prime.

It is a super-2 number, since 2×1919840257² = 7371573224795652098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1919840207) 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, 959920128 + 959920129.

It is an arithmetic number, because the mean of its divisors is an integer number (959920129).

Almost surely, 2^1919840257 is an apocalyptic number.

It is an amenable number.

1919840257 is a deficient number, since it is larger than the sum of its proper divisors (1).

1919840257 is an equidigital number, since it uses as much as digits as its factorization.

1919840257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 181440, while the sum is 46.

The square root of 1919840257 is about 43815.9817532370. The cubic root of 1919840257 is about 1242.8585320754.

The spelling of 1919840257 in words is "one billion, nine hundred nineteen million, eight hundred forty thousand, two hundred fifty-seven".