18538971959 has 2 divisors, whose sum is σ = 18538971960. Its totient is φ = 18538971958.

The previous prime is 18538971929. The next prime is 18538971967. The reversal of 18538971959 is 95917983581.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18538971959 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 18538971895 and 18538971904.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18538971929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9269485979 + 9269485980.

It is an arithmetic number, because the mean of its divisors is an integer number (9269485980).

Almost surely, 2^18538971959 is an apocalyptic number.

18538971959 is a deficient number, since it is larger than the sum of its proper divisors (1).

18538971959 is an equidigital number, since it uses as much as digits as its factorization.

18538971959 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24494400, while the sum is 65.

The spelling of 18538971959 in words is "eighteen billion, five hundred thirty-eight million, nine hundred seventy-one thousand, nine hundred fifty-nine".