1861819423 has 2 divisors, whose sum is σ = 1861819424. Its totient is φ = 1861819422.

The previous prime is 1861819417. The next prime is 1861819441. The reversal of 1861819423 is 3249181681.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1861819423 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1861819423.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1861819403) 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, 930909711 + 930909712.

It is an arithmetic number, because the mean of its divisors is an integer number (930909712).

Almost surely, 2^1861819423 is an apocalyptic number.

1861819423 is a deficient number, since it is larger than the sum of its proper divisors (1).

1861819423 is an equidigital number, since it uses as much as digits as its factorization.

1861819423 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 82944, while the sum is 43.

The square root of 1861819423 is about 43148.8055802243. The cubic root of 1861819423 is about 1230.2098090990.

The spelling of 1861819423 in words is "one billion, eight hundred sixty-one million, eight hundred nineteen thousand, four hundred twenty-three".