17981491885056 has 1584 divisors, whose sum is σ = 66794461552000. Its totient is φ = 4835359162368.

The previous prime is 17981491885009. The next prime is 17981491885081. The reversal of 17981491885056 is 65058819418971.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

17981491885056 is a `hidden beast` number, since 1 + 7 + 9 + 8 + 1 + 491 + 8 + 85 + 0 + 56 = 666.

It is a super-2 number, since 2×17981491885056² (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 a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1057734816760 + ... + 1057734816776.

Almost surely, 2^{17981491885056} is an apocalyptic number.

17981491885056 is a gapful number since it is divisible by the number (16) 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 17981491885056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33397230776000).

17981491885056 is an abundant number, since it is smaller than the sum of its proper divisors (48812969666944).

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

17981491885056 is an frugal number, since it uses more digits than its factorization.

17981491885056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108 (or 29 counting only the distinct ones).

The product of its (nonzero) digits is 174182400, while the sum is 72.

The spelling of 17981491885056 in words is "seventeen trillion, nine hundred eighty-one billion, four hundred ninety-one million, eight hundred eighty-five thousand, fifty-six".