1917820811 has 2 divisors, whose sum is σ = 1917820812. Its totient is φ = 1917820810.

The previous prime is 1917820789. The next prime is 1917820823. The reversal of 1917820811 is 1180287191.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1917820811 - 2³⁰ = 844078987 is a prime.

It is not a weakly prime, because it can be changed into another prime (1917820871) 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, 958910405 + 958910406.

It is an arithmetic number, because the mean of its divisors is an integer number (958910406).

Almost surely, 2^1917820811 is an apocalyptic number.

1917820811 is a deficient number, since it is larger than the sum of its proper divisors (1).

1917820811 is an equidigital number, since it uses as much as digits as its factorization.

1917820811 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 38.

The square root of 1917820811 is about 43792.9310619876. The cubic root of 1917820811 is about 1242.4225988892.

The spelling of 1917820811 in words is "one billion, nine hundred seventeen million, eight hundred twenty thousand, eight hundred eleven".