18509881577896 has 16 divisors (see below), whose sum is σ = 34707101571540. Its totient is φ = 9254654492160.

The previous prime is 18509881577893. The next prime is 18509881577897. The reversal of 18509881577896 is 69877518890581.

It can be written as a sum of positive squares in 2 ways, for example, as 13110699556900 + 5399182020996 = 3620870^2 + 2323614^2 .

It is not an unprimeable number, because it can be changed into a prime (18509881577893) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35512201 + ... + 36029656.

Almost surely, 2^{18509881577896} is an apocalyptic number.

It is an amenable number.

18509881577896 is a deficient number, since it is larger than the sum of its proper divisors (16197219993644).

18509881577896 is a wasteful number, since it uses less digits than its factorization.

18509881577896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71574204 (or 71574200 counting only the distinct ones).

The product of its (nonzero) digits is 2438553600, while the sum is 82.

The spelling of 18509881577896 in words is "eighteen trillion, five hundred nine billion, eight hundred eighty-one million, five hundred seventy-seven thousand, eight hundred ninety-six".