18664100200505 has 4 divisors (see below), whose sum is σ = 22396920240612. Its totient is φ = 14931280160400.

The previous prime is 18664100200381. The next prime is 18664100200541. The reversal of 18664100200505 is 50500200146681.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13412353394944 + 5251746805561 = 3662288^2 + 2291669^2 .

It is not a de Polignac number, because 18664100200505 - 2²⁴ = 18664083423289 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1866410020046 + ... + 1866410020055.

It is an arithmetic number, because the mean of its divisors is an integer number (5599230060153).

Almost surely, 2^{18664100200505} is an apocalyptic number.

It is an amenable number.

18664100200505 is a deficient number, since it is larger than the sum of its proper divisors (3732820040107).

18664100200505 is an equidigital number, since it uses as much as digits as its factorization.

18664100200505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3732820040106.

The product of its (nonzero) digits is 57600, while the sum is 38.

The spelling of 18664100200505 in words is "eighteen trillion, six hundred sixty-four billion, one hundred million, two hundred thousand, five hundred five".