16403523840 has 720 divisors, whose sum is σ = 67489773120. Its totient is φ = 3762339840.

The previous prime is 16403523791. The next prime is 16403523883. The reversal of 16403523840 is 4832530461.

16403523840 is a `hidden beast` number, since 1 + 640 + 3 + 5 + 2 + 3 + 8 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 16403523795 and 16403523804.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 21668742 + ... + 21669498.

It is an arithmetic number, because the mean of its divisors is an integer number (93735796).

Almost surely, 2^16403523840 is an apocalyptic number.

16403523840 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 16403523840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33744886560).

16403523840 is an abundant number, since it is smaller than the sum of its proper divisors (51086249280).

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

16403523840 is a wasteful number, since it uses less digits than its factorization.

16403523840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 820 (or 797 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The spelling of 16403523840 in words is "sixteen billion, four hundred three million, five hundred twenty-three thousand, eight hundred forty".