18844851643665 has 16 divisors (see below), whose sum is σ = 31738697505600. Its totient is φ = 9521609251392.

The previous prime is 18844851643643. The next prime is 18844851643711. The reversal of 18844851643665 is 56634615844881.

It is a happy number.

It is not a de Polignac number, because 18844851643665 - 2⁷ = 18844851643537 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18844851643665.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33061142950 + ... + 33061143519.

It is an arithmetic number, because the mean of its divisors is an integer number (1983668594100).

Almost surely, 2^{18844851643665} is an apocalyptic number.

18844851643665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18844851643665 is a deficient number, since it is larger than the sum of its proper divisors (12893845861935).

18844851643665 is a wasteful number, since it uses less digits than its factorization.

18844851643665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66122286496.

The product of its digits is 530841600, while the sum is 69.

The spelling of 18844851643665 in words is "eighteen trillion, eight hundred forty-four billion, eight hundred fifty-one million, six hundred forty-three thousand, six hundred sixty-five".