18531686960640 has 640 divisors, whose sum is σ = 75960415365120. Its totient is φ = 4194678472704.

The previous prime is 18531686960629. The next prime is 18531686960653. The reversal of 18531686960640 is 4606968613581.

18531686960640 is a `hidden beast` number, since 1 + 8 + 5 + 3 + 16 + 8 + 6 + 9 + 606 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 49649592 + ... + 50021448.

It is an arithmetic number, because the mean of its divisors is an integer number (118688149008).

Almost surely, 2^{18531686960640} is an apocalyptic number.

18531686960640 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 18531686960640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37980207682560).

18531686960640 is an abundant number, since it is smaller than the sum of its proper divisors (57428728404480).

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

18531686960640 is a wasteful number, since it uses less digits than its factorization.

18531686960640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371999 (or 371977 counting only the distinct ones).

The product of its (nonzero) digits is 44789760, while the sum is 63.

The spelling of 18531686960640 in words is "eighteen trillion, five hundred thirty-one billion, six hundred eighty-six million, nine hundred sixty thousand, six hundred forty".