1919287081 has 2 divisors, whose sum is σ = 1919287082. Its totient is φ = 1919287080.

The previous prime is 1919287061. The next prime is 1919287087. The reversal of 1919287081 is 1807829191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1024320025 + 894967056 = 32005^2 + 29916^2 .

It is a cyclic number.

It is not a de Polignac number, because 1919287081 - 2⁷ = 1919286953 is a prime.

It is a super-2 number, since 2×1919287081² = 7367325798587001122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1919287087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 959643540 + 959643541.

It is an arithmetic number, because the mean of its divisors is an integer number (959643541).

Almost surely, 2^1919287081 is an apocalyptic number.

It is an amenable number.

1919287081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1919287081 is an equidigital number, since it uses as much as digits as its factorization.

1919287081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72576, while the sum is 46.

The square root of 1919287081 is about 43809.6688072393. The cubic root of 1919287081 is about 1242.7391496506.

The spelling of 1919287081 in words is "one billion, nine hundred nineteen million, two hundred eighty-seven thousand, eighty-one".