161911680 has 192 divisors, whose sum is σ = 600702480. Its totient is φ = 36986880.

The previous prime is 161911657. The next prime is 161911699. The reversal of 161911680 is 86119161.

It is a tau number, because it is divible by the number of its divisors (192).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 93220 + ... + 94940.

Almost surely, 2^161911680 is an apocalyptic number.

161911680 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 161911680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (300351240).

161911680 is an abundant number, since it is smaller than the sum of its proper divisors (438790800).

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

161911680 is a wasteful number, since it uses less digits than its factorization.

161911680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1757 (or 1738 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 33.

The square root of 161911680 is about 12724.4520510708. The cubic root of 161911680 is about 545.0370931183.

It can be divided in two parts, 16191 and 1680, that added together give a palindrome (17871).

The spelling of 161911680 in words is "one hundred sixty-one million, nine hundred eleven thousand, six hundred eighty".