161522320 has 20 divisors (see below), whose sum is σ = 375539580. Its totient is φ = 64608896.

The previous prime is 161522311. The next prime is 161522341. The reversal of 161522320 is 23225161.

It can be written as a sum of positive squares in 2 ways, for example, as 89340304 + 72182016 = 9452^2 + 8496^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 161522291 and 161522300.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1009435 + ... + 1009594.

It is an arithmetic number, because the mean of its divisors is an integer number (18776979).

Almost surely, 2^161522320 is an apocalyptic number.

161522320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161522320 is an abundant number, since it is smaller than the sum of its proper divisors (214017260).

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

161522320 is a wasteful number, since it uses less digits than its factorization.

161522320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2019042 (or 2019036 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 161522320 is about 12709.1431654538. The cubic root of 161522320 is about 544.5998465486.

Adding to 161522320 its reverse (23225161), we get a palindrome (184747481).

The spelling of 161522320 in words is "one hundred sixty-one million, five hundred twenty-two thousand, three hundred twenty".