161982720 has 288 divisors, whose sum is σ = 593577600. Its totient is φ = 41803776.

The previous prime is 161982703. The next prime is 161982739. The reversal of 161982720 is 27289161.

It is a tau number, because it is divible by the number of its divisors (288).

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

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 31 ways as a sum of consecutive naturals, for example, 1486026 + ... + 1486134.

Almost surely, 2^161982720 is an apocalyptic number.

161982720 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 161982720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (296788800).

161982720 is an abundant number, since it is smaller than the sum of its proper divisors (431594880).

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

161982720 is a wasteful number, since it uses less digits than its factorization.

161982720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182 (or 162 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 161982720 is about 12727.2432207450. The cubic root of 161982720 is about 545.1167945408.

The spelling of 161982720 in words is "one hundred sixty-one million, nine hundred eighty-two thousand, seven hundred twenty".