18359981640 has 1792 divisors, whose sum is σ = 90431147520. Its totient is φ = 3224862720.

The previous prime is 18359981593. The next prime is 18359981699. The reversal of 18359981640 is 4618995381.

18359981640 is a `hidden beast` number, since 1 + 8 + 3 + 599 + 8 + 1 + 6 + 40 = 666.

It is a super-2 number, since 2×18359981640² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 447 ways as a sum of consecutive naturals, for example, 496215702 + ... + 496215738.

It is an arithmetic number, because the mean of its divisors is an integer number (50463810).

Almost surely, 2^18359981640 is an apocalyptic number.

18359981640 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 18359981640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45215573760).

18359981640 is an abundant number, since it is smaller than the sum of its proper divisors (72071165880).

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

18359981640 is a wasteful number, since it uses less digits than its factorization.

18359981640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114 (or 95 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 54.

It can be divided in two parts, 18359 and 981640, that added together give a palindrome (999999).

The spelling of 18359981640 in words is "eighteen billion, three hundred fifty-nine million, nine hundred eighty-one thousand, six hundred forty".