16845668640 has 144 divisors (see below), whose sum is σ = 57725563896. Its totient is φ = 4473446400.

The previous prime is 16845668633. The next prime is 16845668663. The reversal of 16845668640 is 4686654861.

16845668640 is a `hidden beast` number, since 16 + 8 + 4 + 566 + 8 + 64 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 10460380176 + 6385288464 = 102276^2 + 79908^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 322770 + ... + 371310.

Almost surely, 2^16845668640 is an apocalyptic number.

16845668640 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 16845668640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28862781948).

16845668640 is an abundant number, since it is smaller than the sum of its proper divisors (40879895256).

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

16845668640 is a wasteful number, since it uses less digits than its factorization.

16845668640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48803 (or 48792 counting only the distinct ones).

The product of its (nonzero) digits is 6635520, while the sum is 54.

The spelling of 16845668640 in words is "sixteen billion, eight hundred forty-five million, six hundred sixty-eight thousand, six hundred forty".