1861819441 has 2 divisors, whose sum is σ = 1861819442. Its totient is φ = 1861819440.

The previous prime is 1861819423. The next prime is 1861819489. The reversal of 1861819441 is 1449181681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1542839841 + 318979600 = 39279^2 + 17860^2 .

It is an emirp because it is prime and its reverse (1449181681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1861819441 - 2⁷ = 1861819313 is a prime.

It is not a weakly prime, because it can be changed into another prime (1861819411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 930909720 + 930909721.

It is an arithmetic number, because the mean of its divisors is an integer number (930909721).

Almost surely, 2^1861819441 is an apocalyptic number.

It is an amenable number.

1861819441 is a deficient number, since it is larger than the sum of its proper divisors (1).

1861819441 is an equidigital number, since it uses as much as digits as its factorization.

1861819441 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 55296, while the sum is 43.

The square root of 1861819441 is about 43148.8057888049. The cubic root of 1861819441 is about 1230.2098130635.

The spelling of 1861819441 in words is "one billion, eight hundred sixty-one million, eight hundred nineteen thousand, four hundred forty-one".