18215601640 has 128 divisors (see below), whose sum is σ = 43600032000. Its totient is φ = 6834995200.

The previous prime is 18215601533. The next prime is 18215601697. The reversal of 18215601640 is 4610651281.

It is a junction number, because it is equal to n+sod(n) for n = 18215601596 and 18215601605.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11376840 + ... + 11378440.

It is an arithmetic number, because the mean of its divisors is an integer number (340625250).

Almost surely, 2^18215601640 is an apocalyptic number.

18215601640 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 18215601640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21800016000).

18215601640 is an abundant number, since it is smaller than the sum of its proper divisors (25384430360).

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

18215601640 is a wasteful number, since it uses less digits than its factorization.

18215601640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1867 (or 1863 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 34.

The spelling of 18215601640 in words is "eighteen billion, two hundred fifteen million, six hundred one thousand, six hundred forty".