18686438871840 has 288 divisors, whose sum is σ = 64511185415040. Its totient is φ = 4925179650048.

The previous prime is 18686438871829. The next prime is 18686438871899. The reversal of 18686438871840 is 4817883468681.

18686438871840 is a `hidden beast` number, since 1 + 8 + 6 + 8 + 6 + 438 + 8 + 7 + 184 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-2 number, since 2×18686438871840² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 58256539 + ... + 58576421.

It is an arithmetic number, because the mean of its divisors is an integer number (223997171580).

Almost surely, 2^{18686438871840} is an apocalyptic number.

18686438871840 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 18686438871840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32255592707520).

18686438871840 is an abundant number, since it is smaller than the sum of its proper divisors (45824746543200).

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

18686438871840 is a wasteful number, since it uses less digits than its factorization.

18686438871840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320376 (or 320365 counting only the distinct ones).

The product of its (nonzero) digits is 396361728, while the sum is 72.

The spelling of 18686438871840 in words is "eighteen trillion, six hundred eighty-six billion, four hundred thirty-eight million, eight hundred seventy-one thousand, eight hundred forty".