18209908540 has 24 divisors (see below), whose sum is σ = 38962334880. Its totient is φ = 7146529728.

The previous prime is 18209908531. The next prime is 18209908543. The reversal of 18209908540 is 4580990281.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18209908543) 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, 8588520 + ... + 8590639.

It is an arithmetic number, because the mean of its divisors is an integer number (1623430620).

Almost surely, 2^18209908540 is an apocalyptic number.

18209908540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18209908540 is an abundant number, since it is smaller than the sum of its proper divisors (20752426340).

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

18209908540 is a wasteful number, since it uses less digits than its factorization.

18209908540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17179221 (or 17179219 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 46.

The spelling of 18209908540 in words is "eighteen billion, two hundred nine million, nine hundred eight thousand, five hundred forty".