161520256 has 64 divisors (see below), whose sum is σ = 339568200. Its totient is φ = 76410880.

The previous prime is 161520223. The next prime is 161520259. The reversal of 161520256 is 652025161.

It can be written as a sum of positive squares in 4 ways, for example, as 138862656 + 22657600 = 11784^2 + 4760^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (161520259) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 196326 + ... + 197146.

Almost surely, 2^161520256 is an apocalyptic number.

161520256 is a gapful number since it is divisible by the number (16) 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 161520256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169784100).

161520256 is an abundant number, since it is smaller than the sum of its proper divisors (178047944).

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

161520256 is an equidigital number, since it uses as much as digits as its factorization.

161520256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 917 (or 905 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 161520256 is about 12709.0619638115. The cubic root of 161520256 is about 544.5975268303.

The spelling of 161520256 in words is "one hundred sixty-one million, five hundred twenty thousand, two hundred fifty-six".