1618861889 has 2 divisors, whose sum is σ = 1618861890. Its totient is φ = 1618861888.

The previous prime is 1618861879. The next prime is 1618861939. The reversal of 1618861889 is 9881688161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1386817600 + 232044289 = 37240^2 + 15233^2 .

It is a cyclic number.

It is not a de Polignac number, because 1618861889 - 2¹⁶ = 1618796353 is a prime.

It is not a weakly prime, because it can be changed into another prime (1618861879) 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, 809430944 + 809430945.

It is an arithmetic number, because the mean of its divisors is an integer number (809430945).

Almost surely, 2^1618861889 is an apocalyptic number.

It is an amenable number.

1618861889 is a deficient number, since it is larger than the sum of its proper divisors (1).

1618861889 is an equidigital number, since it uses as much as digits as its factorization.

1618861889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1327104, while the sum is 56.

The square root of 1618861889 is about 40235.0828133856. The cubic root of 1618861889 is about 1174.1851937253.

The spelling of 1618861889 in words is "one billion, six hundred eighteen million, eight hundred sixty-one thousand, eight hundred eighty-nine".