16781375520 has 432 divisors, whose sum is σ = 70876233792. Its totient is φ = 3540326400.

The previous prime is 16781375503. The next prime is 16781375539. The reversal of 16781375520 is 2557318761.

It is a happy number.

16781375520 is a `hidden beast` number, since 1 + 67 + 8 + 1 + 37 + 552 + 0 = 666.

16781375520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×16781375520² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1698595 + ... + 1708445.

It is an arithmetic number, because the mean of its divisors is an integer number (164065356).

Almost surely, 2^16781375520 is an apocalyptic number.

16781375520 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 16781375520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35438116896).

16781375520 is an abundant number, since it is smaller than the sum of its proper divisors (54094858272).

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

16781375520 is a wasteful number, since it uses less digits than its factorization.

16781375520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9905 (or 9881 counting only the distinct ones).

The product of its (nonzero) digits is 352800, while the sum is 45.

The spelling of 16781375520 in words is "sixteen billion, seven hundred eighty-one million, three hundred seventy-five thousand, five hundred twenty".