1919478817 has 2 divisors, whose sum is σ = 1919478818. Its totient is φ = 1919478816.

The previous prime is 1919478797. The next prime is 1919478881. The reversal of 1919478817 is 7188749191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1117966096 + 801512721 = 33436^2 + 28311^2 .

It is a cyclic number.

It is not a de Polignac number, because 1919478817 - 2⁷ = 1919478689 is a prime.

It is not a weakly prime, because it can be changed into another prime (1919478217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 959739408 + 959739409.

It is an arithmetic number, because the mean of its divisors is an integer number (959739409).

Almost surely, 2^1919478817 is an apocalyptic number.

It is an amenable number.

1919478817 is a deficient number, since it is larger than the sum of its proper divisors (1).

1919478817 is an equidigital number, since it uses as much as digits as its factorization.

1919478817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1016064, while the sum is 55.

The square root of 1919478817 is about 43811.8570366516. The cubic root of 1919478817 is about 1242.7805313181.

The spelling of 1919478817 in words is "one billion, nine hundred nineteen million, four hundred seventy-eight thousand, eight hundred seventeen".