18591457889 has 2 divisors, whose sum is σ = 18591457890. Its totient is φ = 18591457888.

The previous prime is 18591457861. The next prime is 18591457903. The reversal of 18591457889 is 98875419581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11877294289 + 6714163600 = 108983^2 + 81940^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18591457889 is a prime.

It is not a weakly prime, because it can be changed into another prime (18590457889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9295728944 + 9295728945.

It is an arithmetic number, because the mean of its divisors is an integer number (9295728945).

Almost surely, 2^18591457889 is an apocalyptic number.

It is an amenable number.

18591457889 is a deficient number, since it is larger than the sum of its proper divisors (1).

18591457889 is an equidigital number, since it uses as much as digits as its factorization.

18591457889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 29030400, while the sum is 65.

The spelling of 18591457889 in words is "eighteen billion, five hundred ninety-one million, four hundred fifty-seven thousand, eight hundred eighty-nine".