18644084917 has 4 divisors (see below), whose sum is σ = 18836292076. Its totient is φ = 18451877760.

The previous prime is 18644084903. The next prime is 18644084923. The reversal of 18644084917 is 71948044681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71948044681 = 53 ⋅1357510277.

It can be written as a sum of positive squares in 2 ways, for example, as 2920429681 + 15723655236 = 54041^2 + 125394^2 .

It is a cyclic number.

It is not a de Polignac number, because 18644084917 - 2³¹ = 16496601269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18644084117) 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, 96103434 + ... + 96103627.

It is an arithmetic number, because the mean of its divisors is an integer number (4709073019).

Almost surely, 2^18644084917 is an apocalyptic number.

It is an amenable number.

18644084917 is a deficient number, since it is larger than the sum of its proper divisors (192207159).

18644084917 is an equidigital number, since it uses as much as digits as its factorization.

18644084917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192207158.

The product of its (nonzero) digits is 1548288, while the sum is 52.

The spelling of 18644084917 in words is "eighteen billion, six hundred forty-four million, eighty-four thousand, nine hundred seventeen".