18585997920 has 864 divisors, whose sum is σ = 79054859520. Its totient is φ = 3955875840.

The previous prime is 18585997919. The next prime is 18585997921. The reversal of 18585997920 is 2979958581.

18585997920 is a `hidden beast` number, since 18 + 5 + 8 + 599 + 7 + 9 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (18585997919) and next prime (18585997921).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18585997921) by changing a digit.

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 143 ways as a sum of consecutive naturals, for example, 63433294 + ... + 63433586.

It is an arithmetic number, because the mean of its divisors is an integer number (91498680).

Almost surely, 2^18585997920 is an apocalyptic number.

18585997920 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 18585997920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39527429760).

18585997920 is an abundant number, since it is smaller than the sum of its proper divisors (60468861600).

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

18585997920 is a wasteful number, since it uses less digits than its factorization.

18585997920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 388 (or 370 counting only the distinct ones).

The product of its (nonzero) digits is 16329600, while the sum is 63.

The spelling of 18585997920 in words is "eighteen billion, five hundred eighty-five million, nine hundred ninety-seven thousand, nine hundred twenty".