161908259408640 has 864 divisors, whose sum is σ = 587409098411520. Its totient is φ = 42221929881600.

The previous prime is 161908259408629. The next prime is 161908259408741. The reversal of 161908259408640 is 46804952809161.

161908259408640 is a `hidden beast` number, since 1 + 6 + 1 + 90 + 82 + 5 + 9 + 408 + 64 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

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 95 ways as a sum of consecutive naturals, for example, 39576692995 + ... + 39576697085.

It is an arithmetic number, because the mean of its divisors is an integer number (679871641680).

Almost surely, 2^{161908259408640} is an apocalyptic number.

161908259408640 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 161908259408640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (293704549205760).

161908259408640 is an abundant number, since it is smaller than the sum of its proper divisors (425500839002880).

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

161908259408640 is an equidigital number, since it uses as much as digits as its factorization.

161908259408640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4446 (or 4299 counting only the distinct ones).

The product of its (nonzero) digits is 29859840, while the sum is 63.

The spelling of 161908259408640 in words is "one hundred sixty-one trillion, nine hundred eight billion, two hundred fifty-nine million, four hundred eight thousand, six hundred forty".