18105628644 has 18 divisors (see below), whose sum is σ = 45767005830. Its totient is φ = 6035209536.

The previous prime is 18105628603. The next prime is 18105628699. The reversal of 18105628644 is 44682650181.

It is a happy number.

18105628644 is a `hidden beast` number, since 1 + 8 + 1 + 0 + 562 + 86 + 4 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 18095630400 + 9998244 = 134520^2 + 3162^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 18105628644.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 251467029 + ... + 251467100.

It is an arithmetic number, because the mean of its divisors is an integer number (2542611435).

Almost surely, 2^18105628644 is an apocalyptic number.

It is an amenable number.

18105628644 is an abundant number, since it is smaller than the sum of its proper divisors (27661377186).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18105628644 is a wasteful number, since it uses less digits than its factorization.

18105628644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 502934139 (or 502934134 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The spelling of 18105628644 in words is "eighteen billion, one hundred five million, six hundred twenty-eight thousand, six hundred forty-four".