18685969537 has 2 divisors, whose sum is σ = 18685969538. Its totient is φ = 18685969536.

The previous prime is 18685969531. The next prime is 18685969567. The reversal of 18685969537 is 73596958681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18669396496 + 16573041 = 136636^2 + 4071^2 .

It is a cyclic number.

It is not a de Polignac number, because 18685969537 - 2⁷ = 18685969409 is a prime.

It is not a weakly prime, because it can be changed into another prime (18685969531) 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, 9342984768 + 9342984769.

It is an arithmetic number, because the mean of its divisors is an integer number (9342984769).

Almost surely, 2^18685969537 is an apocalyptic number.

It is an amenable number.

18685969537 is a deficient number, since it is larger than the sum of its proper divisors (1).

18685969537 is an equidigital number, since it uses as much as digits as its factorization.

18685969537 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 97977600, while the sum is 67.

The spelling of 18685969537 in words is "eighteen billion, six hundred eighty-five million, nine hundred sixty-nine thousand, five hundred thirty-seven".