18105646720 has 128 divisors (see below), whose sum is σ = 51063321600. Its totient is φ = 6007357440.

The previous prime is 18105646673. The next prime is 18105646723. The reversal of 18105646720 is 2764650181.

It is a tau number, because it is divible by the number of its divisors (128).

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (18105646723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 73696 + ... + 204064.

It is an arithmetic number, because the mean of its divisors is an integer number (398932200).

Almost surely, 2^18105646720 is an apocalyptic number.

18105646720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18105646720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25531660800).

18105646720 is an abundant number, since it is smaller than the sum of its proper divisors (32957674880).

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

18105646720 is a wasteful number, since it uses less digits than its factorization.

18105646720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130426 (or 130414 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 40.

The spelling of 18105646720 in words is "eighteen billion, one hundred five million, six hundred forty-six thousand, seven hundred twenty".