18643648240 has 40 divisors (see below), whose sum is σ = 49538838240. Its totient is φ = 6392107776.

The previous prime is 18643648211. The next prime is 18643648241. The reversal of 18643648240 is 4284634681.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (46) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18643648241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16645555 + ... + 16646674.

It is an arithmetic number, because the mean of its divisors is an integer number (1238470956).

Almost surely, 2^18643648240 is an apocalyptic number.

18643648240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18643648240 is an abundant number, since it is smaller than the sum of its proper divisors (30895190000).

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

18643648240 is a wasteful number, since it uses less digits than its factorization.

18643648240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33292249 (or 33292243 counting only the distinct ones).

The product of its (nonzero) digits is 884736, while the sum is 46.

The spelling of 18643648240 in words is "eighteen billion, six hundred forty-three million, six hundred forty-eight thousand, two hundred forty".