161225512180 has 48 divisors (see below), whose sum is σ = 355046544720. Its totient is φ = 61413424128.

The previous prime is 161225512153. The next prime is 161225512199. The reversal of 161225512180 is 81215522161.

It can be written as a sum of positive squares in 8 ways, for example, as 5481625444 + 155743886736 = 74038^2 + 394644^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1861599 + ... + 1946278.

It is an arithmetic number, because the mean of its divisors is an integer number (7396803015).

Almost surely, 2^161225512180 is an apocalyptic number.

161225512180 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161225512180 is an abundant number, since it is smaller than the sum of its proper divisors (193821032540).

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

161225512180 is a wasteful number, since it uses less digits than its factorization.

161225512180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3807988 (or 3807986 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 34.

The spelling of 161225512180 in words is "one hundred sixty-one billion, two hundred twenty-five million, five hundred twelve thousand, one hundred eighty".