163681309440 has 2304 divisors, whose sum is σ = 745965158400. Its totient is φ = 33443020800.

The previous prime is 163681309439. The next prime is 163681309513. The reversal of 163681309440 is 44903186361.

163681309440 is a `hidden beast` number, since 1 + 636 + 8 + 1 + 3 + 0 + 9 + 4 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (2304).

It is a super-2 number, since 2×163681309440² (a number of 23 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 (13) of ones.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 3806542059 + ... + 3806542101.

It is an arithmetic number, because the mean of its divisors is an integer number (323769600).

Almost surely, 2^163681309440 is an apocalyptic number.

163681309440 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 163681309440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (372982579200).

163681309440 is an abundant number, since it is smaller than the sum of its proper divisors (582283848960).

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

163681309440 is a wasteful number, since it uses less digits than its factorization.

163681309440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The spelling of 163681309440 in words is "one hundred sixty-three billion, six hundred eighty-one million, three hundred nine thousand, four hundred forty".