18211985280 has 192 divisors, whose sum is σ = 63167457600. Its totient is φ = 4834971648.

The previous prime is 18211985269. The next prime is 18211985287. The reversal of 18211985280 is 8258911281.

18211985280 is a `hidden beast` number, since 1 + 8 + 2 + 119 + 8 + 528 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

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 (18211985287) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1312137 + ... + 1325943.

It is an arithmetic number, because the mean of its divisors is an integer number (328997175).

Almost surely, 2^18211985280 is an apocalyptic number.

18211985280 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 18211985280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31583728800).

18211985280 is an abundant number, since it is smaller than the sum of its proper divisors (44955472320).

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

18211985280 is a wasteful number, since it uses less digits than its factorization.

18211985280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14061 (or 14046 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 45.

The spelling of 18211985280 in words is "eighteen billion, two hundred eleven million, nine hundred eighty-five thousand, two hundred eighty".