18685931220 has 576 divisors, whose sum is σ = 66691392768. Its totient is φ = 4193280000.

The previous prime is 18685931189. The next prime is 18685931227. The reversal of 18685931220 is 2213958681.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18685931227) 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 191 ways as a sum of consecutive naturals, for example, 185009170 + ... + 185009270.

It is an arithmetic number, because the mean of its divisors is an integer number (115783668).

Almost surely, 2^18685931220 is an apocalyptic number.

18685931220 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 18685931220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33345696384).

18685931220 is an abundant number, since it is smaller than the sum of its proper divisors (48005461548).

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

18685931220 is a wasteful number, since it uses less digits than its factorization.

18685931220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264 (or 259 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The spelling of 18685931220 in words is "eighteen billion, six hundred eighty-five million, nine hundred thirty-one thousand, two hundred twenty".