16991563680 has 576 divisors, whose sum is σ = 71996940288. Its totient is φ = 3553320960.

The previous prime is 16991563661. The next prime is 16991563709. The reversal of 16991563680 is 8636519961.

16991563680 is a `hidden beast` number, since 16 + 9 + 9 + 1 + 563 + 68 + 0 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 16641570 + ... + 16642590.

It is an arithmetic number, because the mean of its divisors is an integer number (124994688).

Almost surely, 2^16991563680 is an apocalyptic number.

16991563680 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 16991563680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35998470144).

16991563680 is an abundant number, since it is smaller than the sum of its proper divisors (55005376608).

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

16991563680 is a wasteful number, since it uses less digits than its factorization.

16991563680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1189 (or 1178 counting only the distinct ones).

The product of its (nonzero) digits is 2099520, while the sum is 54.

The spelling of 16991563680 in words is "sixteen billion, nine hundred ninety-one million, five hundred sixty-three thousand, six hundred eighty".