161280720 has 100 divisors (see below), whose sum is σ = 560174340. Its totient is φ = 43006464.

The previous prime is 161280701. The next prime is 161280731. The reversal of 161280720 is 27082161.

161280720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 19289664 + 141991056 = 4392^2 + 11916^2 .

It is a super-3 number, since 3×161280720³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 5965 + ... + 18924.

Almost surely, 2^161280720 is an apocalyptic number.

161280720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161280720 is an abundant number, since it is smaller than the sum of its proper divisors (398893620).

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

161280720 is a wasteful number, since it uses less digits than its factorization.

161280720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24914 (or 24899 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 161280720 is about 12699.6346404139. The cubic root of 161280720 is about 544.3281792860.

The spelling of 161280720 in words is "one hundred sixty-one million, two hundred eighty thousand, seven hundred twenty".