10991991759840 has 576 divisors, whose sum is σ = 47610305971200. Its totient is φ = 2319188391936.

The previous prime is 10991991759829. The next prime is 10991991759857. The reversal of 10991991759840 is 4895719919901.

10991991759840 is a `hidden beast` number, since 1 + 0 + 9 + 9 + 19 + 9 + 17 + 598 + 4 + 0 = 666.

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 95 ways as a sum of consecutive naturals, for example, 4035141 + ... + 6185979.

It is an arithmetic number, because the mean of its divisors is an integer number (82656781200).

Almost surely, 2^{10991991759840} is an apocalyptic number.

10991991759840 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 10991991759840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23805152985600).

10991991759840 is an abundant number, since it is smaller than the sum of its proper divisors (36618314211360).

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

10991991759840 is a wasteful number, since it uses less digits than its factorization.

10991991759840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2150896 (or 2150869 counting only the distinct ones).

The product of its (nonzero) digits is 66134880, while the sum is 72.

The spelling of 10991991759840 in words is "ten trillion, nine hundred ninety-one billion, nine hundred ninety-one million, seven hundred fifty-nine thousand, eight hundred forty".