18684881820 has 192 divisors, whose sum is σ = 64612961280. Its totient is φ = 4444128000.

The previous prime is 18684881797. The next prime is 18684881821. The reversal of 18684881820 is 2818848681.

18684881820 is a `hidden beast` number, since 1 + 86 + 8 + 488 + 1 + 82 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18684881821) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 285145 + ... + 344495.

It is an arithmetic number, because the mean of its divisors is an integer number (336525840).

Almost surely, 2^18684881820 is an apocalyptic number.

18684881820 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 18684881820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32306480640).

18684881820 is an abundant number, since it is smaller than the sum of its proper divisors (45928079460).

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

18684881820 is a wasteful number, since it uses less digits than its factorization.

18684881820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59433 (or 59425 counting only the distinct ones).

The product of its (nonzero) digits is 1572864, while the sum is 54.

The spelling of 18684881820 in words is "eighteen billion, six hundred eighty-four million, eight hundred eighty-one thousand, eight hundred twenty".